From fb41e55a2da70a345f30153786372c94781920fe Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Thu, 20 Jul 2017 22:45:01 +0200
Subject: [PATCH 01/20] mingw: explicitly specify with which cmd to prefix the
 cmdline

The main idea of this patch is that even if we have to look up the
absolute path of the script, if only the basename was specified as
argv[0], then we should use that basename on the command line, too, not
the absolute path.

This patch will also help with the upcoming patch where we automatically
substitute "sh ..." by "busybox sh ..." if "sh" is not in the PATH but
"busybox" is: we will do that by substituting the actual executable, but
still keep prepending "sh" to the command line.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 compat/mingw.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/compat/mingw.c b/compat/mingw.c
index f76b630dc0..05d4bf2fe9 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -1856,8 +1856,8 @@ static int is_msys2_sh(const char *cmd)
 }
 
 static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **deltaenv,
-			      const char *dir,
-			      int prepend_cmd, int fhin, int fhout, int fherr)
+			      const char *dir, const char *prepend_cmd,
+			      int fhin, int fhout, int fherr)
 {
 	static int restrict_handle_inheritance = -1;
 	STARTUPINFOEXW si;
@@ -1948,9 +1948,9 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **deltaen
 	/* concatenate argv, quoting args as we go */
 	strbuf_init(&args, 0);
 	if (prepend_cmd) {
-		char *quoted = (char *)quote_arg(cmd);
+		char *quoted = (char *)quote_arg(prepend_cmd);
 		strbuf_addstr(&args, quoted);
-		if (quoted != cmd)
+		if (quoted != prepend_cmd)
 			free(quoted);
 	}
 	for (; *argv; argv++) {
@@ -2109,7 +2109,8 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **deltaen
 	return (pid_t)pi.dwProcessId;
 }
 
-static pid_t mingw_spawnv(const char *cmd, const char **argv, int prepend_cmd)
+static pid_t mingw_spawnv(const char *cmd, const char **argv,
+			  const char *prepend_cmd)
 {
 	return mingw_spawnve_fd(cmd, argv, NULL, NULL, prepend_cmd, 0, 1, 2);
 }
@@ -2137,14 +2138,14 @@ pid_t mingw_spawnvpe(const char *cmd, const char **argv, char **deltaenv,
 				pid = -1;
 			}
 			else {
-				pid = mingw_spawnve_fd(iprog, argv, deltaenv, dir, 1,
+				pid = mingw_spawnve_fd(iprog, argv, deltaenv, dir, interpr,
 						       fhin, fhout, fherr);
 				free(iprog);
 			}
 			argv[0] = argv0;
 		}
 		else
-			pid = mingw_spawnve_fd(prog, argv, deltaenv, dir, 0,
+			pid = mingw_spawnve_fd(prog, argv, deltaenv, dir, NULL,
 					       fhin, fhout, fherr);
 		free(prog);
 	}
@@ -2172,7 +2173,7 @@ static int try_shell_exec(const char *cmd, char *const *argv)
 		argv2[0] = (char *)cmd;	/* full path to the script file */
 		COPY_ARRAY(&argv2[1], &argv[1], argc);
 		exec_id = trace2_exec(prog, argv2);
-		pid = mingw_spawnv(prog, argv2, 1);
+		pid = mingw_spawnv(prog, argv2, interpr);
 		if (pid >= 0) {
 			int status;
 			if (waitpid(pid, &status, 0) < 0)
@@ -2196,7 +2197,7 @@ int mingw_execv(const char *cmd, char *const *argv)
 		int exec_id;
 
 		exec_id = trace2_exec(cmd, (const char **)argv);
-		pid = mingw_spawnv(cmd, (const char **)argv, 0);
+		pid = mingw_spawnv(cmd, (const char **)argv, NULL);
 		if (pid < 0) {
 			trace2_exec_result(exec_id, -1);
 			return -1;

From 192d5167644000500a029c66df5c7dbb0af255c4 Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Thu, 20 Jul 2017 20:41:29 +0200
Subject: [PATCH 02/20] mingw: when path_lookup() failed, try BusyBox

BusyBox comes with a ton of applets ("applet" being the identical
concept to Git's "builtins"). And similar to Git's builtins, the applets
can be called via `busybox <command>`, or the BusyBox executable can be
copied/hard-linked to the command name.

The similarities do not end here. Just as with Git's builtins, it is
problematic that BusyBox' hard-linked applets cannot easily be put into
a .zip file: .zip archives have no concept of hard-links and therefore
would store identical copies (and also extract identical copies,
"inflating" the archive unnecessarily).

To counteract that issue, MinGit already ships without hard-linked
copies of the builtins, and the plan is to do the same with BusyBox'
applets: simply ship busybox.exe as single executable, without
hard-linked applets.

To accommodate that, Git is being taught by this commit a very special
trick, exploiting the fact that it is possible to call an executable
with a command-line whose argv[0] is different from the executable's
name: when `sh` is to be spawned, and no `sh` is found in the PATH, but
busybox.exe is, use that executable (with unchanged argv).

Likewise, if any executable to be spawned is not on the PATH, but
busybox.exe is found, parse the output of `busybox.exe --help` to find
out what applets are included, and if the command matches an included
applet name, use busybox.exe to execute it.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 compat/mingw.c   | 63 ++++++++++++++++++++++++++++++++++++++++++++++++
 t/t0014-alias.sh |  2 +-
 2 files changed, 64 insertions(+), 1 deletion(-)

diff --git a/compat/mingw.c b/compat/mingw.c
index 05d4bf2fe9..cd26f80b85 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -15,6 +15,7 @@
 #include <sspi.h>
 #include "win32/fscache.h"
 #include "../attr.h"
+#include "../string-list.h"
 
 #define HCAST(type, handle) ((type)(intptr_t)handle)
 
@@ -1629,6 +1630,65 @@ static char *lookup_prog(const char *dir, int dirlen, const char *cmd,
 	return NULL;
 }
 
+static char *path_lookup(const char *cmd, int exe_only);
+
+static char *is_busybox_applet(const char *cmd)
+{
+	static struct string_list applets = STRING_LIST_INIT_DUP;
+	static char *busybox_path;
+	static int busybox_path_initialized;
+
+	/* Avoid infinite loop */
+	if (!strncasecmp(cmd, "busybox", 7) &&
+	    (!cmd[7] || !strcasecmp(cmd + 7, ".exe")))
+		return NULL;
+
+	if (!busybox_path_initialized) {
+		busybox_path = path_lookup("busybox.exe", 1);
+		busybox_path_initialized = 1;
+	}
+
+	/* Assume that sh is compiled in... */
+	if (!busybox_path || !strcasecmp(cmd, "sh"))
+		return xstrdup_or_null(busybox_path);
+
+	if (!applets.nr) {
+		struct child_process cp = CHILD_PROCESS_INIT;
+		struct strbuf buf = STRBUF_INIT;
+		char *p;
+
+		strvec_pushl(&cp.args, busybox_path, "--help", NULL);
+
+		if (capture_command(&cp, &buf, 2048)) {
+			string_list_append(&applets, "");
+			return NULL;
+		}
+
+		/* parse output */
+		p = strstr(buf.buf, "Currently defined functions:\n");
+		if (!p) {
+			warning("Could not parse output of busybox --help");
+			string_list_append(&applets, "");
+			return NULL;
+		}
+		p = strchrnul(p, '\n');
+		for (;;) {
+			size_t len;
+
+			p += strspn(p, "\n\t ,");
+			len = strcspn(p, "\n\t ,");
+			if (!len)
+				break;
+			p[len] = '\0';
+			string_list_insert(&applets, p);
+			p = p + len + 1;
+		}
+	}
+
+	return string_list_has_string(&applets, cmd) ?
+		xstrdup(busybox_path) : NULL;
+}
+
 /*
  * Determines the absolute path of cmd using the split path in path.
  * If cmd contains a slash or backslash, no lookup is performed.
@@ -1657,6 +1717,9 @@ static char *path_lookup(const char *cmd, int exe_only)
 		path = sep + 1;
 	}
 
+	if (!prog && !isexe)
+		prog = is_busybox_applet(cmd);
+
 	return prog;
 }
 
diff --git a/t/t0014-alias.sh b/t/t0014-alias.sh
index 288e08299a..06669cab78 100755
--- a/t/t0014-alias.sh
+++ b/t/t0014-alias.sh
@@ -39,7 +39,7 @@ test_expect_success 'looping aliases - internal execution' '
 
 test_expect_success 'run-command formats empty args properly' '
 	test_must_fail env GIT_TRACE=1 git frotz a "" b " " c 2>actual.raw &&
-	sed -ne "/run_command:/s/.*trace: run_command: //p" actual.raw >actual &&
+	sed -ne "/run_command: git-frotz/s/.*trace: run_command: //p" actual.raw >actual &&
 	echo "git-frotz a '\'''\'' b '\'' '\'' c" >expect &&
 	test_cmp expect actual
 '

From 512efa0d2d12c65430caa08d06874e6730a60e1b Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Sat, 5 Aug 2017 22:23:36 +0200
Subject: [PATCH 03/20] test-lib: avoid unnecessary Perl invocation

It is a bit strange, and even undesirable, to require Perl just to run
the test suite even when NO_PERL was set.

This patch does not fix this problem by any stretch of imagination.
However, it fixes *the* Perl invocation that *every single* test script
has to run.

While at it, it makes the source code also more grep'able, as the code
that unsets some, but not all, GIT_* environment variables just became a
*lot* more explicit. And all that while still reducing the total number
of lines.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 t/test-lib.sh | 29 ++++++++++++-----------------
 1 file changed, 12 insertions(+), 17 deletions(-)

diff --git a/t/test-lib.sh b/t/test-lib.sh
index 6db377f68b..59d7b45708 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -496,23 +496,18 @@ EDITOR=:
 # /usr/xpg4/bin/sh and /bin/ksh to bail out.  So keep the unsets
 # deriving from the command substitution clustered with the other
 # ones.
-unset VISUAL EMAIL LANGUAGE $("$PERL_PATH" -e '
-	my @env = keys %ENV;
-	my $ok = join("|", qw(
-		TRACE
-		DEBUG
-		TEST
-		.*_TEST
-		PROVE
-		VALGRIND
-		UNZIP
-		PERF_
-		CURL_VERBOSE
-		TRACE_CURL
-	));
-	my @vars = grep(/^GIT_/ && !/^GIT_($ok)/o, @env);
-	print join("\n", @vars);
-')
+unset VISUAL EMAIL LANGUAGE $(env | sed -n \
+	-e '/^GIT_TRACE/d' \
+	-e '/^GIT_DEBUG/d' \
+	-e '/^GIT_TEST/d' \
+	-e '/^GIT_.*_TEST/d' \
+	-e '/^GIT_PROVE/d' \
+	-e '/^GIT_VALGRIND/d' \
+	-e '/^GIT_UNZIP/d' \
+	-e '/^GIT_PERF_/d' \
+	-e '/^GIT_CURL_VERBOSE/d' \
+	-e '/^GIT_TRACE_CURL/d' \
+	-e 's/^\(GIT_[^=]*\)=.*/\1/p')
 unset XDG_CACHE_HOME
 unset XDG_CONFIG_HOME
 unset GITPERLLIB

From c84d752d4100bc2f99ca0faac8d222c27fc120f6 Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Thu, 7 Jun 2018 10:47:25 +0200
Subject: [PATCH 04/20] tests: replace mingw_test_cmp with a helper in C

This helper is slightly more performant than the script with MSYS2's
Bash. And a lot more readable.

To accommodate t1050, which wants to compare files weighing in with 3MB
(falling outside of t1050's malloc limit of 1.5MB), we simply lift the
allocation limit by setting the environment variable GIT_ALLOC_LIMIT to
zero when calling the helper.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 Makefile                |  1 +
 t/helper/test-cmp.c     | 66 +++++++++++++++++++++++++++++++++++++++
 t/helper/test-tool.c    |  1 +
 t/helper/test-tool.h    |  1 +
 t/test-lib-functions.sh | 68 +----------------------------------------
 t/test-lib.sh           |  2 +-
 6 files changed, 71 insertions(+), 68 deletions(-)
 create mode 100644 t/helper/test-cmp.c

diff --git a/Makefile b/Makefile
index 13b2df4bfb..11a094207d 100644
--- a/Makefile
+++ b/Makefile
@@ -789,6 +789,7 @@ TEST_BUILTINS_OBJS += test-bloom.o
 TEST_BUILTINS_OBJS += test-bundle-uri.o
 TEST_BUILTINS_OBJS += test-cache-tree.o
 TEST_BUILTINS_OBJS += test-chmtime.o
+TEST_BUILTINS_OBJS += test-cmp.o
 TEST_BUILTINS_OBJS += test-config.o
 TEST_BUILTINS_OBJS += test-crontab.o
 TEST_BUILTINS_OBJS += test-csprng.o
diff --git a/t/helper/test-cmp.c b/t/helper/test-cmp.c
new file mode 100644
index 0000000000..717e9f18fb
--- /dev/null
+++ b/t/helper/test-cmp.c
@@ -0,0 +1,66 @@
+#include "test-tool.h"
+#include "git-compat-util.h"
+#include "strbuf.h"
+#include "gettext.h"
+#include "parse-options.h"
+#include "run-command.h"
+
+#ifdef WIN32
+#define NO_SUCH_DIR "\\\\.\\GLOBALROOT\\invalid"
+#else
+#define NO_SUCH_DIR "/dev/null"
+#endif
+
+static int run_diff(const char *path1, const char *path2)
+{
+	struct child_process cmd = CHILD_PROCESS_INIT;
+
+	cmd.git_cmd = 1;
+	cmd.no_stdin = 1;
+	strvec_pushl(&cmd.args, "diff", "--no-index", path1, path2, NULL);
+	strvec_pushl(&cmd.env, "GIT_PAGER=cat", "GIT_DIR=" NO_SUCH_DIR,
+		     "HOME=" NO_SUCH_DIR, NULL);
+	return run_command(&cmd);
+}
+
+int cmd__cmp(int argc, const char **argv)
+{
+	FILE *f0, *f1;
+	struct strbuf b0 = STRBUF_INIT, b1 = STRBUF_INIT;
+
+	if (argc != 3)
+		die("Require exactly 2 arguments, got %d", argc);
+
+	if (!(f0 = !strcmp(argv[1], "-") ? stdin : fopen(argv[1], "r")))
+		return error_errno("could not open '%s'", argv[1]);
+	if (!(f1 = !strcmp(argv[2], "-") ? stdin : fopen(argv[2], "r"))) {
+		fclose(f0);
+		return error_errno("could not open '%s'", argv[2]);
+	}
+
+	for (;;) {
+		int r0 = strbuf_getline(&b0, f0);
+		int r1 = strbuf_getline(&b1, f1);
+
+		if (r0 == EOF) {
+			fclose(f0);
+			fclose(f1);
+			strbuf_release(&b0);
+			strbuf_release(&b1);
+			if (r1 == EOF)
+				return 0;
+cmp_failed:
+			if (!run_diff(argv[1], argv[2]))
+				die("Huh? 'diff --no-index %s %s' succeeded",
+				    argv[1], argv[2]);
+			return 1;
+		}
+		if (r1 == EOF || strbuf_cmp(&b0, &b1)) {
+			fclose(f0);
+			fclose(f1);
+			strbuf_release(&b0);
+			strbuf_release(&b1);
+			goto cmp_failed;
+		}
+	}
+}
diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c
index 7eb1a26a30..59c39bdca4 100644
--- a/t/helper/test-tool.c
+++ b/t/helper/test-tool.c
@@ -16,6 +16,7 @@ static struct test_cmd cmds[] = {
 	{ "bundle-uri", cmd__bundle_uri },
 	{ "cache-tree", cmd__cache_tree },
 	{ "chmtime", cmd__chmtime },
+	{ "cmp", cmd__cmp },
 	{ "config", cmd__config },
 	{ "crontab", cmd__crontab },
 	{ "csprng", cmd__csprng },
diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h
index 2e20a16eb8..7298439877 100644
--- a/t/helper/test-tool.h
+++ b/t/helper/test-tool.h
@@ -9,6 +9,7 @@ int cmd__bloom(int argc, const char **argv);
 int cmd__bundle_uri(int argc, const char **argv);
 int cmd__cache_tree(int argc, const char **argv);
 int cmd__chmtime(int argc, const char **argv);
+int cmd__cmp(int argc, const char **argv);
 int cmd__config(int argc, const char **argv);
 int cmd__crontab(int argc, const char **argv);
 int cmd__csprng(int argc, const char **argv);
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 796093a7b3..0410447fa6 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -1149,7 +1149,7 @@ test_expect_code () {
 
 test_cmp () {
 	test "$#" -ne 2 && BUG "2 param"
-	eval "$GIT_TEST_CMP" '"$@"'
+	GIT_ALLOC_LIMIT=0 eval "$GIT_TEST_CMP" '"$@"'
 }
 
 # Check that the given config key has the expected value.
@@ -1450,72 +1450,6 @@ test_skip_or_die () {
 	error "$2"
 }
 
-# The following mingw_* functions obey POSIX shell syntax, but are actually
-# bash scripts, and are meant to be used only with bash on Windows.
-
-# A test_cmp function that treats LF and CRLF equal and avoids to fork
-# diff when possible.
-mingw_test_cmp () {
-	# Read text into shell variables and compare them. If the results
-	# are different, use regular diff to report the difference.
-	local test_cmp_a= test_cmp_b=
-
-	# When text came from stdin (one argument is '-') we must feed it
-	# to diff.
-	local stdin_for_diff=
-
-	# Since it is difficult to detect the difference between an
-	# empty input file and a failure to read the files, we go straight
-	# to diff if one of the inputs is empty.
-	if test -s "$1" && test -s "$2"
-	then
-		# regular case: both files non-empty
-		mingw_read_file_strip_cr_ test_cmp_a <"$1"
-		mingw_read_file_strip_cr_ test_cmp_b <"$2"
-	elif test -s "$1" && test "$2" = -
-	then
-		# read 2nd file from stdin
-		mingw_read_file_strip_cr_ test_cmp_a <"$1"
-		mingw_read_file_strip_cr_ test_cmp_b
-		stdin_for_diff='<<<"$test_cmp_b"'
-	elif test "$1" = - && test -s "$2"
-	then
-		# read 1st file from stdin
-		mingw_read_file_strip_cr_ test_cmp_a
-		mingw_read_file_strip_cr_ test_cmp_b <"$2"
-		stdin_for_diff='<<<"$test_cmp_a"'
-	fi
-	test -n "$test_cmp_a" &&
-	test -n "$test_cmp_b" &&
-	test "$test_cmp_a" = "$test_cmp_b" ||
-	eval "diff -u \"\$@\" $stdin_for_diff"
-}
-
-# $1 is the name of the shell variable to fill in
-mingw_read_file_strip_cr_ () {
-	# Read line-wise using LF as the line separator
-	# and use IFS to strip CR.
-	local line
-	while :
-	do
-		if IFS=$'\r' read -r -d $'\n' line
-		then
-			# good
-			line=$line$'\n'
-		else
-			# we get here at EOF, but also if the last line
-			# was not terminated by LF; in the latter case,
-			# some text was read
-			if test -z "$line"
-			then
-				# EOF, really
-				break
-			fi
-		fi
-		eval "$1=\$$1\$line"
-	done
-}
-
 # Like "env FOO=BAR some-program", but run inside a subshell, which means
 # it also works for shell functions (though those functions cannot impact
 # the environment outside of the test_env invocation).
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 59d7b45708..01e241aa94 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1716,7 +1716,7 @@ case $uname_s in
 	test_set_prereq SED_STRIPS_CR
 	test_set_prereq GREP_STRIPS_CR
 	test_set_prereq WINDOWS
-	GIT_TEST_CMP=mingw_test_cmp
+	GIT_TEST_CMP="test-tool cmp"
 	;;
 *CYGWIN*)
 	test_set_prereq POSIXPERM

From 5788fb267fbefe2e1f5536bfc5bdc6b2e49ff7ad Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Thu, 20 Jul 2017 22:18:56 +0200
Subject: [PATCH 05/20] test-tool: learn to act as a drop-in replacement for
 `iconv`

It is convenient to assume that everybody who wants to build & test Git
has access to a working `iconv` executable (after all, we already pretty
much require libiconv).

However, that limits esoteric test scenarios such as Git for Windows',
where an end user installation has to ship with `iconv` for the sole
purpose of being testable. That payload serves no other purpose.

So let's just have a test helper (to be able to test Git, the test
helpers have to be available, after all) to act as `iconv` replacement.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 Makefile              |  1 +
 t/helper/test-iconv.c | 47 +++++++++++++++++++++++++++++++++++++++++++
 t/helper/test-tool.c  |  1 +
 t/helper/test-tool.h  |  1 +
 4 files changed, 50 insertions(+)
 create mode 100644 t/helper/test-iconv.c

diff --git a/Makefile b/Makefile
index 11a094207d..d8526207b0 100644
--- a/Makefile
+++ b/Makefile
@@ -812,6 +812,7 @@ TEST_BUILTINS_OBJS += test-hash-speed.o
 TEST_BUILTINS_OBJS += test-hash.o
 TEST_BUILTINS_OBJS += test-hashmap.o
 TEST_BUILTINS_OBJS += test-hexdump.o
+TEST_BUILTINS_OBJS += test-iconv.o
 TEST_BUILTINS_OBJS += test-index-version.o
 TEST_BUILTINS_OBJS += test-json-writer.o
 TEST_BUILTINS_OBJS += test-lazy-init-name-hash.o
diff --git a/t/helper/test-iconv.c b/t/helper/test-iconv.c
new file mode 100644
index 0000000000..d3c772fddf
--- /dev/null
+++ b/t/helper/test-iconv.c
@@ -0,0 +1,47 @@
+#include "test-tool.h"
+#include "git-compat-util.h"
+#include "strbuf.h"
+#include "gettext.h"
+#include "parse-options.h"
+#include "utf8.h"
+
+int cmd__iconv(int argc, const char **argv)
+{
+	struct strbuf buf = STRBUF_INIT;
+	char *from = NULL, *to = NULL, *p;
+	size_t len;
+	int ret = 0;
+	const char * const iconv_usage[] = {
+		N_("test-helper --iconv [<options>]"),
+		NULL
+	};
+	struct option options[] = {
+		OPT_STRING('f', "from-code", &from, "encoding", "from"),
+		OPT_STRING('t', "to-code", &to, "encoding", "to"),
+		OPT_END()
+	};
+
+	argc = parse_options(argc, argv, NULL, options,
+			iconv_usage, 0);
+
+	if (argc > 1 || !from || !to)
+		usage_with_options(iconv_usage, options);
+
+	if (!argc) {
+		if (strbuf_read(&buf, 0, 2048) < 0)
+			die_errno("Could not read from stdin");
+	} else if (strbuf_read_file(&buf, argv[0], 2048) < 0)
+		die_errno("Could not read from '%s'", argv[0]);
+
+	p = reencode_string_len(buf.buf, buf.len, to, from, &len);
+	if (!p)
+		die_errno("Could not reencode");
+	if (write(1, p, len) < 0)
+		ret = !!error_errno("Could not write %"PRIuMAX" bytes",
+				    (uintmax_t)len);
+
+	strbuf_release(&buf);
+	free(p);
+
+	return ret;
+}
diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c
index 59c39bdca4..4ad9f8b6f3 100644
--- a/t/helper/test-tool.c
+++ b/t/helper/test-tool.c
@@ -38,6 +38,7 @@ static struct test_cmd cmds[] = {
 	{ "hashmap", cmd__hashmap },
 	{ "hash-speed", cmd__hash_speed },
 	{ "hexdump", cmd__hexdump },
+	{ "iconv", cmd__iconv },
 	{ "index-version", cmd__index_version },
 	{ "json-writer", cmd__json_writer },
 	{ "lazy-init-name-hash", cmd__lazy_init_name_hash },
diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h
index 7298439877..03de377214 100644
--- a/t/helper/test-tool.h
+++ b/t/helper/test-tool.h
@@ -32,6 +32,7 @@ int cmd__getcwd(int argc, const char **argv);
 int cmd__hashmap(int argc, const char **argv);
 int cmd__hash_speed(int argc, const char **argv);
 int cmd__hexdump(int argc, const char **argv);
+int cmd__iconv(int argc, const char **argv);
 int cmd__index_version(int argc, const char **argv);
 int cmd__json_writer(int argc, const char **argv);
 int cmd__lazy_init_name_hash(int argc, const char **argv);

From a5904f7a4216c78f5d804510530796d2c79b86ce Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Thu, 20 Jul 2017 22:25:21 +0200
Subject: [PATCH 06/20] tests(mingw): if `iconv` is unavailable, use
 `test-helper --iconv`

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 t/test-lib.sh | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/t/test-lib.sh b/t/test-lib.sh
index 01e241aa94..e4dcf3d2e2 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1717,6 +1717,12 @@ case $uname_s in
 	test_set_prereq GREP_STRIPS_CR
 	test_set_prereq WINDOWS
 	GIT_TEST_CMP="test-tool cmp"
+	if ! type iconv >/dev/null 2>&1
+	then
+		iconv () {
+			test-tool iconv "$@"
+		}
+	fi
 	;;
 *CYGWIN*)
 	test_set_prereq POSIXPERM

From 254c34503716d091513e5caa0b4b1a335299da6d Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Thu, 11 Oct 2018 23:55:44 +0200
Subject: [PATCH 07/20] gitattributes: mark .png files as binary

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 .gitattributes | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.gitattributes b/.gitattributes
index b0044cf272..2bc4defac6 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -4,6 +4,7 @@
 *.perl eol=lf diff=perl
 *.pl eof=lf diff=perl
 *.pm eol=lf diff=perl
+*.png binary
 *.py eol=lf diff=python
 *.bat eol=crlf
 CODE_OF_CONDUCT.md -whitespace

From cbe15930e01b777c9c827f1bcceca086765a5373 Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Sat, 5 Aug 2017 20:28:37 +0200
Subject: [PATCH 08/20] tests: move test PNGs into t/lib-diff/

We already have a directory where we store files intended for use by
multiple test scripts. The same directory is a better home for the
test-binary-*.png files than t/.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 t/{ => lib-diff}/test-binary-1.png | Bin
 t/{ => lib-diff}/test-binary-2.png | Bin
 t/t3307-notes-man.sh               |   2 +-
 t/t3903-stash.sh                   |   2 +-
 t/t4012-diff-binary.sh             |   2 +-
 t/t4049-diff-stat-count.sh         |   2 +-
 t/t4108-apply-threeway.sh          |  12 ++++++------
 t/t6403-merge-file.sh              |   2 +-
 t/t6407-merge-binary.sh            |   2 +-
 t/t9200-git-cvsexportcommit.sh     |  15 ++++++++-------
 10 files changed, 20 insertions(+), 19 deletions(-)
 rename t/{ => lib-diff}/test-binary-1.png (100%)
 rename t/{ => lib-diff}/test-binary-2.png (100%)

diff --git a/t/test-binary-1.png b/t/lib-diff/test-binary-1.png
similarity index 100%
rename from t/test-binary-1.png
rename to t/lib-diff/test-binary-1.png
diff --git a/t/test-binary-2.png b/t/lib-diff/test-binary-2.png
similarity index 100%
rename from t/test-binary-2.png
rename to t/lib-diff/test-binary-2.png
diff --git a/t/t3307-notes-man.sh b/t/t3307-notes-man.sh
index ae316502c4..2b6894df0a 100755
--- a/t/t3307-notes-man.sh
+++ b/t/t3307-notes-man.sh
@@ -27,7 +27,7 @@ test_expect_success 'example 1: notes to add an Acked-by line' '
 '
 
 test_expect_success 'example 2: binary notes' '
-	cp "$TEST_DIRECTORY"/test-binary-1.png . &&
+	cp "$TEST_DIRECTORY"/lib-diff/test-binary-1.png . &&
 	git checkout B &&
 	blob=$(git hash-object -w test-binary-1.png) &&
 	git notes --ref=logo add -C "$blob" &&
diff --git a/t/t3903-stash.sh b/t/t3903-stash.sh
index 376cc8f4ab..4e49ac1b11 100755
--- a/t/t3903-stash.sh
+++ b/t/t3903-stash.sh
@@ -1332,7 +1332,7 @@ test_expect_success 'stash -- <subdir> works with binary files' '
 	git reset &&
 	>subdir/untracked &&
 	>subdir/tracked &&
-	cp "$TEST_DIRECTORY"/test-binary-1.png subdir/tracked-binary &&
+	cp "$TEST_DIRECTORY"/lib-diff/test-binary-1.png subdir/tracked-binary &&
 	git add subdir/tracked* &&
 	git stash -- subdir/ &&
 	test_path_is_missing subdir/tracked &&
diff --git a/t/t4012-diff-binary.sh b/t/t4012-diff-binary.sh
index c64d9d2f40..b3b9adc3c0 100755
--- a/t/t4012-diff-binary.sh
+++ b/t/t4012-diff-binary.sh
@@ -20,7 +20,7 @@ test_expect_success 'prepare repository' '
 	echo AIT >a && echo BIT >b && echo CIT >c && echo DIT >d &&
 	git update-index --add a b c d &&
 	echo git >a &&
-	cat "$TEST_DIRECTORY"/test-binary-1.png >b &&
+	cat "$TEST_DIRECTORY"/lib-diff/test-binary-1.png >b &&
 	echo git >c &&
 	cat b b >d
 '
diff --git a/t/t4049-diff-stat-count.sh b/t/t4049-diff-stat-count.sh
index 0a4fc735d4..6c02864648 100755
--- a/t/t4049-diff-stat-count.sh
+++ b/t/t4049-diff-stat-count.sh
@@ -34,7 +34,7 @@ test_expect_success 'binary changes do not count in lines' '
 	git reset --hard &&
 	echo a >a &&
 	echo c >c &&
-	cat "$TEST_DIRECTORY"/test-binary-1.png >d &&
+	cat "$TEST_DIRECTORY"/lib-diff/test-binary-1.png >d &&
 	cat >expect <<-\EOF &&
 	 a | 1 +
 	 c | 1 +
diff --git a/t/t4108-apply-threeway.sh b/t/t4108-apply-threeway.sh
index c558282bc0..1c85e7051d 100755
--- a/t/t4108-apply-threeway.sh
+++ b/t/t4108-apply-threeway.sh
@@ -232,11 +232,11 @@ test_expect_success 'apply with --3way --cached and conflicts' '
 
 test_expect_success 'apply binary file patch' '
 	git reset --hard main &&
-	cp "$TEST_DIRECTORY/test-binary-1.png" bin.png &&
+	cp "$TEST_DIRECTORY/lib-diff/test-binary-1.png" bin.png &&
 	git add bin.png &&
 	git commit -m "add binary file" &&
 
-	cp "$TEST_DIRECTORY/test-binary-2.png" bin.png &&
+	cp "$TEST_DIRECTORY/lib-diff/test-binary-2.png" bin.png &&
 
 	git diff --binary >bin.diff &&
 	git reset --hard &&
@@ -247,11 +247,11 @@ test_expect_success 'apply binary file patch' '
 
 test_expect_success 'apply binary file patch with 3way' '
 	git reset --hard main &&
-	cp "$TEST_DIRECTORY/test-binary-1.png" bin.png &&
+	cp "$TEST_DIRECTORY/lib-diff/test-binary-1.png" bin.png &&
 	git add bin.png &&
 	git commit -m "add binary file" &&
 
-	cp "$TEST_DIRECTORY/test-binary-2.png" bin.png &&
+	cp "$TEST_DIRECTORY/lib-diff/test-binary-2.png" bin.png &&
 
 	git diff --binary >bin.diff &&
 	git reset --hard &&
@@ -262,11 +262,11 @@ test_expect_success 'apply binary file patch with 3way' '
 
 test_expect_success 'apply full-index patch with 3way' '
 	git reset --hard main &&
-	cp "$TEST_DIRECTORY/test-binary-1.png" bin.png &&
+	cp "$TEST_DIRECTORY/lib-diff/test-binary-1.png" bin.png &&
 	git add bin.png &&
 	git commit -m "add binary file" &&
 
-	cp "$TEST_DIRECTORY/test-binary-2.png" bin.png &&
+	cp "$TEST_DIRECTORY/lib-diff/test-binary-2.png" bin.png &&
 
 	git diff --full-index >bin.diff &&
 	git reset --hard &&
diff --git a/t/t6403-merge-file.sh b/t/t6403-merge-file.sh
index 1a7082323d..a6854952c9 100755
--- a/t/t6403-merge-file.sh
+++ b/t/t6403-merge-file.sh
@@ -252,7 +252,7 @@ test_expect_success "expected conflict markers" '
 
 test_expect_success 'binary files cannot be merged' '
 	test_must_fail git merge-file -p \
-		orig.txt "$TEST_DIRECTORY"/test-binary-1.png new1.txt 2> merge.err &&
+		orig.txt "$TEST_DIRECTORY"/lib-diff/test-binary-1.png new1.txt 2> merge.err &&
 	grep "Cannot merge binary files" merge.err
 '
 
diff --git a/t/t6407-merge-binary.sh b/t/t6407-merge-binary.sh
index e8a28717ce..2547f1d504 100755
--- a/t/t6407-merge-binary.sh
+++ b/t/t6407-merge-binary.sh
@@ -9,7 +9,7 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
 test_expect_success setup '
 
-	cat "$TEST_DIRECTORY"/test-binary-1.png >m &&
+	cat "$TEST_DIRECTORY"/lib-diff/test-binary-1.png >m &&
 	git add m &&
 	git ls-files -s | sed -e "s/ 0	/ 1	/" >E1 &&
 	test_tick &&
diff --git a/t/t9200-git-cvsexportcommit.sh b/t/t9200-git-cvsexportcommit.sh
index c5946cb0b8..3e1034e6b4 100755
--- a/t/t9200-git-cvsexportcommit.sh
+++ b/t/t9200-git-cvsexportcommit.sh
@@ -55,8 +55,8 @@ test_expect_success \
     'mkdir A B C D E F &&
      echo hello1 >A/newfile1.txt &&
      echo hello2 >B/newfile2.txt &&
-     cp "$TEST_DIRECTORY"/test-binary-1.png C/newfile3.png &&
-     cp "$TEST_DIRECTORY"/test-binary-1.png D/newfile4.png &&
+     cp "$TEST_DIRECTORY"/lib-diff/test-binary-1.png C/newfile3.png &&
+     cp "$TEST_DIRECTORY"/lib-diff/test-binary-1.png D/newfile4.png &&
      git add A/newfile1.txt &&
      git add B/newfile2.txt &&
      git add C/newfile3.png &&
@@ -81,8 +81,8 @@ test_expect_success \
      rm -f B/newfile2.txt &&
      rm -f C/newfile3.png &&
      echo Hello5  >E/newfile5.txt &&
-     cp "$TEST_DIRECTORY"/test-binary-2.png D/newfile4.png &&
-     cp "$TEST_DIRECTORY"/test-binary-1.png F/newfile6.png &&
+     cp "$TEST_DIRECTORY"/lib-diff/test-binary-2.png D/newfile4.png &&
+     cp "$TEST_DIRECTORY"/lib-diff/test-binary-1.png F/newfile6.png &&
      git add E/newfile5.txt &&
      git add F/newfile6.png &&
      git commit -a -m "Test: Remove, add and update" &&
@@ -170,7 +170,7 @@ test_expect_success \
      'mkdir "G g" &&
       echo ok then >"G g/with spaces.txt" &&
       git add "G g/with spaces.txt" && \
-      cp "$TEST_DIRECTORY"/test-binary-1.png "G g/with spaces.png" && \
+      cp "$TEST_DIRECTORY"/lib-diff/test-binary-1.png "G g/with spaces.png" && \
       git add "G g/with spaces.png" &&
       git commit -a -m "With spaces" &&
       id=$(git rev-list --max-count=1 HEAD) &&
@@ -182,7 +182,8 @@ test_expect_success \
 test_expect_success \
      'Update file with spaces in file name' \
      'echo Ok then >>"G g/with spaces.txt" &&
-      cat "$TEST_DIRECTORY"/test-binary-1.png >>"G g/with spaces.png" && \
+      cat "$TEST_DIRECTORY"/lib-diff/test-binary-1.png \
+	>>"G g/with spaces.png" && \
       git add "G g/with spaces.png" &&
       git commit -a -m "Update with spaces" &&
       id=$(git rev-list --max-count=1 HEAD) &&
@@ -207,7 +208,7 @@ test_expect_success !MINGW \
      'mkdir -p Å/goo/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z/å/ä/ö &&
       echo Foo >Å/goo/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z/å/ä/ö/gårdetsågårdet.txt &&
       git add Å/goo/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z/å/ä/ö/gårdetsågårdet.txt &&
-      cp "$TEST_DIRECTORY"/test-binary-1.png Å/goo/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z/å/ä/ö/gårdetsågårdet.png &&
+      cp "$TEST_DIRECTORY"/lib-diff/test-binary-1.png Å/goo/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z/å/ä/ö/gårdetsågårdet.png &&
       git add Å/goo/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z/å/ä/ö/gårdetsågårdet.png &&
       git commit -a -m "Går det så går det" && \
       id=$(git rev-list --max-count=1 HEAD) &&

From 47dc5babf1e2dc5b1f710d2302ab72fa038087e5 Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Tue, 18 Jul 2017 01:15:40 +0200
Subject: [PATCH 09/20] tests: only override sort & find if there are usable
 ones in /usr/bin/

The idea is to allow running the test suite on MinGit with BusyBox
installed in /mingw64/bin/sh.exe. In that case, we will want to exclude
sort & find (and other Unix utilities) from being bundled.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 git-sh-setup.sh | 21 ++++++++++++++-------
 t/test-lib.sh   | 21 ++++++++++++++-------
 2 files changed, 28 insertions(+), 14 deletions(-)

diff --git a/git-sh-setup.sh b/git-sh-setup.sh
index ce273fe0e4..785a4cbfa9 100644
--- a/git-sh-setup.sh
+++ b/git-sh-setup.sh
@@ -292,13 +292,20 @@ create_virtual_base() {
 # Platform specific tweaks to work around some commands
 case $(uname -s) in
 *MINGW*)
-	# Windows has its own (incompatible) sort and find
-	sort () {
-		/usr/bin/sort "$@"
-	}
-	find () {
-		/usr/bin/find "$@"
-	}
+	if test -x /usr/bin/sort
+	then
+		# Windows has its own (incompatible) sort; override
+		sort () {
+			/usr/bin/sort "$@"
+		}
+	fi
+	if test -x /usr/bin/find
+	then
+		# Windows has its own (incompatible) find; override
+		find () {
+			/usr/bin/find "$@"
+		}
+	fi
 	# git sees Windows-style pwd
 	pwd () {
 		builtin pwd -W
diff --git a/t/test-lib.sh b/t/test-lib.sh
index e4dcf3d2e2..673ac43456 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1697,13 +1697,20 @@ fi
 uname_s=$(uname -s)
 case $uname_s in
 *MINGW*)
-	# Windows has its own (incompatible) sort and find
-	sort () {
-		/usr/bin/sort "$@"
-	}
-	find () {
-		/usr/bin/find "$@"
-	}
+	if test -x /usr/bin/sort
+	then
+		# Windows has its own (incompatible) sort; override
+		sort () {
+			/usr/bin/sort "$@"
+		}
+	fi
+	if test -x /usr/bin/find
+	then
+		# Windows has its own (incompatible) find; override
+		find () {
+			/usr/bin/find "$@"
+		}
+	fi
 	# git sees Windows-style pwd
 	pwd () {
 		builtin pwd -W

From f6554f959b6e667b044f5b0e8656d54862fd0f5e Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Mon, 19 Nov 2018 20:34:13 +0100
Subject: [PATCH 10/20] tests: use the correct path separator with BusyBox

BusyBox-w32 is a true Win32 application, i.e. it does not come with a
POSIX emulation layer.

That also means that it does *not* use the Unix convention of separating
the entries in the PATH variable using colons, but semicolons.

However, there are also BusyBox ports to Windows which use a POSIX
emulation layer such as Cygwin's or MSYS2's runtime, i.e. using colons
as PATH separators.

As a tell-tale, let's use the presence of semicolons in the PATH
variable: on Unix, it is highly unlikely that it contains semicolons,
and on Windows (without POSIX emulation), it is virtually guaranteed, as
everybody should have both $SYSTEMROOT and $SYSTEMROOT/system32 in their
PATH.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 t/interop/interop-lib.sh    |  8 ++++++--
 t/lib-proto-disable.sh      |  2 +-
 t/t0021-conversion.sh       |  2 +-
 t/t0060-path-utils.sh       | 24 ++++++++++++------------
 t/t0061-run-command.sh      |  6 +++---
 t/t0300-credentials.sh      |  2 +-
 t/t1504-ceiling-dirs.sh     | 10 +++++-----
 t/t2300-cd-to-toplevel.sh   |  2 +-
 t/t3402-rebase-merge.sh     |  2 +-
 t/t3418-rebase-continue.sh  |  8 ++++----
 t/t5615-alternate-env.sh    |  4 ++--
 t/t5802-connect-helper.sh   |  2 +-
 t/t7006-pager.sh            |  4 ++--
 t/t7606-merge-custom.sh     |  2 +-
 t/t7811-grep-open.sh        |  2 +-
 t/t9003-help-autocorrect.sh |  2 +-
 t/t9800-git-p4-basic.sh     |  2 +-
 t/test-lib.sh               | 17 +++++++++++++----
 18 files changed, 57 insertions(+), 44 deletions(-)

diff --git a/t/interop/interop-lib.sh b/t/interop/interop-lib.sh
index 3e0a2911d4..dea8883821 100644
--- a/t/interop/interop-lib.sh
+++ b/t/interop/interop-lib.sh
@@ -4,6 +4,10 @@
 . ../../GIT-BUILD-OPTIONS
 INTEROP_ROOT=$(pwd)
 BUILD_ROOT=$INTEROP_ROOT/build
+case "$PATH" in
+*\;*) PATH_SEP=\; ;;
+*) PATH_SEP=: ;;
+esac
 
 build_version () {
 	if test -z "$1"
@@ -57,7 +61,7 @@ wrap_git () {
 	write_script "$1" <<-EOF
 	GIT_EXEC_PATH="$2"
 	export GIT_EXEC_PATH
-	PATH="$2:\$PATH"
+	PATH="$2$PATH_SEP\$PATH"
 	export GIT_EXEC_PATH
 	exec git "\$@"
 	EOF
@@ -71,7 +75,7 @@ generate_wrappers () {
 	echo >&2 fatal: test tried to run generic git
 	exit 1
 	EOF
-	PATH=$(pwd)/.bin:$PATH
+	PATH=$(pwd)/.bin$PATH_SEP$PATH
 }
 
 VERSION_A=${GIT_TEST_VERSION_A:-$VERSION_A}
diff --git a/t/lib-proto-disable.sh b/t/lib-proto-disable.sh
index 890622be81..9db481e1be 100644
--- a/t/lib-proto-disable.sh
+++ b/t/lib-proto-disable.sh
@@ -214,7 +214,7 @@ setup_ext_wrapper () {
 		cd "$TRASH_DIRECTORY/remote" &&
 		eval "$*"
 		EOF
-		PATH=$TRASH_DIRECTORY:$PATH &&
+		PATH=$TRASH_DIRECTORY$PATH_SEP$PATH &&
 		export TRASH_DIRECTORY
 	'
 }
diff --git a/t/t0021-conversion.sh b/t/t0021-conversion.sh
index abecd75e4e..c8560d57cb 100755
--- a/t/t0021-conversion.sh
+++ b/t/t0021-conversion.sh
@@ -9,7 +9,7 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 . "$TEST_DIRECTORY"/lib-terminal.sh
 
 TEST_ROOT="$PWD"
-PATH=$TEST_ROOT:$PATH
+PATH=$TEST_ROOT$PATH_SEP$PATH
 
 write_script <<\EOF "$TEST_ROOT/rot13.sh"
 tr \
diff --git a/t/t0060-path-utils.sh b/t/t0060-path-utils.sh
index d7c581b61e..48433abca1 100755
--- a/t/t0060-path-utils.sh
+++ b/t/t0060-path-utils.sh
@@ -139,25 +139,25 @@ ancestor /foo /fo -1
 ancestor /foo /foo -1
 ancestor /foo /bar -1
 ancestor /foo /foo/bar -1
-ancestor /foo /foo:/bar -1
-ancestor /foo /:/foo:/bar 0
-ancestor /foo /foo:/:/bar 0
-ancestor /foo /:/bar:/foo 0
+ancestor /foo "/foo$PATH_SEP/bar" -1
+ancestor /foo "/$PATH_SEP/foo$PATH_SEP/bar" 0
+ancestor /foo "/foo$PATH_SEP/$PATH_SEP/bar" 0
+ancestor /foo "/$PATH_SEP/bar$PATH_SEP/foo" 0
 ancestor /foo/bar / 0
 ancestor /foo/bar /fo -1
 ancestor /foo/bar /foo 4
 ancestor /foo/bar /foo/ba -1
-ancestor /foo/bar /:/fo 0
-ancestor /foo/bar /foo:/foo/ba 4
+ancestor /foo/bar "/$PATH_SEP/fo" 0
+ancestor /foo/bar "/foo$PATH_SEP/foo/ba" 4
 ancestor /foo/bar /bar -1
 ancestor /foo/bar /fo -1
-ancestor /foo/bar /foo:/bar 4
-ancestor /foo/bar /:/foo:/bar 4
-ancestor /foo/bar /foo:/:/bar 4
-ancestor /foo/bar /:/bar:/fo 0
-ancestor /foo/bar /:/bar 0
+ancestor /foo/bar "/foo$PATH_SEP/bar" 4
+ancestor /foo/bar "/$PATH_SEP/foo$PATH_SEP/bar" 4
+ancestor /foo/bar "/foo$PATH_SEP/$PATH_SEP/bar" 4
+ancestor /foo/bar "/$PATH_SEP/bar$PATH_SEP/fo" 0
+ancestor /foo/bar "/$PATH_SEP/bar" 0
 ancestor /foo/bar /foo 4
-ancestor /foo/bar /foo:/bar 4
+ancestor /foo/bar "/foo$PATH_SEP/bar" 4
 ancestor /foo/bar /bar -1
 
 # Windows-specific: DOS drives, network shares
diff --git a/t/t0061-run-command.sh b/t/t0061-run-command.sh
index e2411f6a9b..3a5c8ab2d5 100755
--- a/t/t0061-run-command.sh
+++ b/t/t0061-run-command.sh
@@ -70,7 +70,7 @@ test_expect_success 'run_command does not try to execute a directory' '
 	cat bin2/greet
 	EOF
 
-	PATH=$PWD/bin1:$PWD/bin2:$PATH \
+	PATH=$PWD/bin1$PATH_SEP$PWD/bin2$PATH_SEP$PATH \
 		test-tool run-command run-command greet >actual 2>err &&
 	test_cmp bin2/greet actual &&
 	test_must_be_empty err
@@ -87,7 +87,7 @@ test_expect_success POSIXPERM 'run_command passes over non-executable file' '
 	cat bin2/greet
 	EOF
 
-	PATH=$PWD/bin1:$PWD/bin2:$PATH \
+	PATH=$PWD/bin1$PATH_SEP$PWD/bin2$PATH_SEP$PATH \
 		test-tool run-command run-command greet >actual 2>err &&
 	test_cmp bin2/greet actual &&
 	test_must_be_empty err
@@ -107,7 +107,7 @@ test_expect_success POSIXPERM,SANITY 'unreadable directory in PATH' '
 	git config alias.nitfol "!echo frotz" &&
 	chmod a-rx local-command &&
 	(
-		PATH=./local-command:$PATH &&
+		PATH=./local-command$PATH_SEP$PATH &&
 		git nitfol >actual
 	) &&
 	echo frotz >expect &&
diff --git a/t/t0300-credentials.sh b/t/t0300-credentials.sh
index 3485c0534e..ed045188e0 100755
--- a/t/t0300-credentials.sh
+++ b/t/t0300-credentials.sh
@@ -35,7 +35,7 @@ test_expect_success 'setup helper scripts' '
 	test -z "$pass" || echo password=$pass
 	EOF
 
-	PATH="$PWD:$PATH"
+	PATH="$PWD$PATH_SEP$PATH"
 '
 
 test_expect_success 'credential_fill invokes helper' '
diff --git a/t/t1504-ceiling-dirs.sh b/t/t1504-ceiling-dirs.sh
index 0fafcf9dde..060296febc 100755
--- a/t/t1504-ceiling-dirs.sh
+++ b/t/t1504-ceiling-dirs.sh
@@ -81,9 +81,9 @@ then
 	GIT_CEILING_DIRECTORIES="$TRASH_ROOT/top/"
 	test_fail subdir_ceil_at_top_slash
 
-	GIT_CEILING_DIRECTORIES=":$TRASH_ROOT/top"
+	GIT_CEILING_DIRECTORIES="$PATH_SEP$TRASH_ROOT/top"
 	test_prefix subdir_ceil_at_top_no_resolve "sub/dir/"
-	GIT_CEILING_DIRECTORIES=":$TRASH_ROOT/top/"
+	GIT_CEILING_DIRECTORIES="$PATH_SEP$TRASH_ROOT/top/"
 	test_prefix subdir_ceil_at_top_slash_no_resolve "sub/dir/"
 fi
 
@@ -113,13 +113,13 @@ GIT_CEILING_DIRECTORIES="$TRASH_ROOT/subdi"
 test_prefix subdir_ceil_at_subdi_slash "sub/dir/"
 
 
-GIT_CEILING_DIRECTORIES="/foo:$TRASH_ROOT/sub"
+GIT_CEILING_DIRECTORIES="/foo$PATH_SEP$TRASH_ROOT/sub"
 test_fail second_of_two
 
-GIT_CEILING_DIRECTORIES="$TRASH_ROOT/sub:/bar"
+GIT_CEILING_DIRECTORIES="$TRASH_ROOT/sub$PATH_SEP/bar"
 test_fail first_of_two
 
-GIT_CEILING_DIRECTORIES="/foo:$TRASH_ROOT/sub:/bar"
+GIT_CEILING_DIRECTORIES="/foo$PATH_SEP$TRASH_ROOT/sub$PATH_SEP/bar"
 test_fail second_of_three
 
 
diff --git a/t/t2300-cd-to-toplevel.sh b/t/t2300-cd-to-toplevel.sh
index b40eeb263f..4328b9172a 100755
--- a/t/t2300-cd-to-toplevel.sh
+++ b/t/t2300-cd-to-toplevel.sh
@@ -17,7 +17,7 @@ test_cd_to_toplevel () {
 	test_expect_success $3 "$2" '
 		(
 			cd '"'$1'"' &&
-			PATH="$EXEC_PATH:$PATH" &&
+			PATH="$EXEC_PATH$PATH_SEP$PATH" &&
 			. git-sh-setup &&
 			cd_to_toplevel &&
 			[ "$(pwd -P)" = "$TOPLEVEL" ]
diff --git a/t/t3402-rebase-merge.sh b/t/t3402-rebase-merge.sh
index 7e46f4ca85..ce553b6edd 100755
--- a/t/t3402-rebase-merge.sh
+++ b/t/t3402-rebase-merge.sh
@@ -146,7 +146,7 @@ test_expect_success 'rebase -s funny -Xopt' '
 	git checkout -b test-funny main^ &&
 	test_commit funny &&
 	(
-		PATH=./test-bin:$PATH &&
+		PATH=./test-bin$PATH_SEP$PATH &&
 		git rebase -s funny -Xopt main
 	) &&
 	test -f funny.was.run
diff --git a/t/t3418-rebase-continue.sh b/t/t3418-rebase-continue.sh
index 130e2f9b55..f1c1eff4ee 100755
--- a/t/t3418-rebase-continue.sh
+++ b/t/t3418-rebase-continue.sh
@@ -73,7 +73,7 @@ test_expect_success 'rebase --continue remembers merge strategy and options' '
 	EOF
 	chmod +x test-bin/git-merge-funny &&
 	(
-		PATH=./test-bin:$PATH &&
+		PATH=./test-bin$PATH_SEP$PATH &&
 		test_must_fail git rebase -s funny -Xopt main topic
 	) &&
 	test -f funny.was.run &&
@@ -81,7 +81,7 @@ test_expect_success 'rebase --continue remembers merge strategy and options' '
 	echo "Resolved" >F2 &&
 	git add F2 &&
 	(
-		PATH=./test-bin:$PATH &&
+		PATH=./test-bin$PATH_SEP$PATH &&
 		git rebase --continue
 	) &&
 	test -f funny.was.run
@@ -105,7 +105,7 @@ test_expect_success 'rebase -i --continue handles merge strategy and options' '
 	EOF
 	chmod +x test-bin/git-merge-funny &&
 	(
-		PATH=./test-bin:$PATH &&
+		PATH=./test-bin$PATH_SEP$PATH &&
 		test_must_fail git rebase -i -s funny -Xopt -Xfoo main topic
 	) &&
 	test -f funny.was.run &&
@@ -113,7 +113,7 @@ test_expect_success 'rebase -i --continue handles merge strategy and options' '
 	echo "Resolved" >F2 &&
 	git add F2 &&
 	(
-		PATH=./test-bin:$PATH &&
+		PATH=./test-bin$PATH_SEP$PATH &&
 		git rebase --continue
 	) &&
 	test -f funny.was.run
diff --git a/t/t5615-alternate-env.sh b/t/t5615-alternate-env.sh
index 83513e46a3..fa2dd08084 100755
--- a/t/t5615-alternate-env.sh
+++ b/t/t5615-alternate-env.sh
@@ -40,7 +40,7 @@ test_expect_success 'access alternate via absolute path' '
 '
 
 test_expect_success 'access multiple alternates' '
-	check_obj "$PWD/one.git/objects:$PWD/two.git/objects" <<-EOF
+	check_obj "$PWD/one.git/objects$PATH_SEP$PWD/two.git/objects" <<-EOF
 	$one blob
 	$two blob
 	EOF
@@ -76,7 +76,7 @@ test_expect_success 'access alternate via relative path (subdir)' '
 quoted='"one.git\057objects"'
 unquoted='two.git/objects'
 test_expect_success 'mix of quoted and unquoted alternates' '
-	check_obj "$quoted:$unquoted" <<-EOF
+	check_obj "$quoted$PATH_SEP$unquoted" <<-EOF
 	$one blob
 	$two blob
 	EOF
diff --git a/t/t5802-connect-helper.sh b/t/t5802-connect-helper.sh
index c6c2661878..a096eeeeb4 100755
--- a/t/t5802-connect-helper.sh
+++ b/t/t5802-connect-helper.sh
@@ -85,7 +85,7 @@ test_expect_success 'set up fake git-daemon' '
 		"$TRASH_DIRECTORY/remote"
 	EOF
 	export TRASH_DIRECTORY &&
-	PATH=$TRASH_DIRECTORY:$PATH
+	PATH=$TRASH_DIRECTORY$PATH_SEP$PATH
 '
 
 test_expect_success 'ext command can connect to git daemon (no vhost)' '
diff --git a/t/t7006-pager.sh b/t/t7006-pager.sh
index e56ca5b0fa..2a90dc74f2 100755
--- a/t/t7006-pager.sh
+++ b/t/t7006-pager.sh
@@ -54,7 +54,7 @@ test_expect_success !MINGW,TTY 'LESS and LV envvars set by git-sh-setup' '
 		sane_unset LESS LV &&
 		PAGER="env >pager-env.out; wc" &&
 		export PAGER &&
-		PATH="$(git --exec-path):$PATH" &&
+		PATH="$(git --exec-path)$PATH_SEP$PATH" &&
 		export PATH &&
 		test_terminal sh -c ". git-sh-setup && git_pager"
 	) &&
@@ -388,7 +388,7 @@ test_default_pager() {
 		EOF
 		chmod +x \$less &&
 		(
-			PATH=.:\$PATH &&
+			PATH=.$PATH_SEP\$PATH &&
 			export PATH &&
 			$full_command
 		) &&
diff --git a/t/t7606-merge-custom.sh b/t/t7606-merge-custom.sh
index 81fb7c474c..8197a1c46b 100755
--- a/t/t7606-merge-custom.sh
+++ b/t/t7606-merge-custom.sh
@@ -23,7 +23,7 @@ test_expect_success 'set up custom strategy' '
 	EOF
 
 	chmod +x git-merge-theirs &&
-	PATH=.:$PATH &&
+	PATH=.$PATH_SEP$PATH &&
 	export PATH
 '
 
diff --git a/t/t7811-grep-open.sh b/t/t7811-grep-open.sh
index 1dd07141a7..668de47c42 100755
--- a/t/t7811-grep-open.sh
+++ b/t/t7811-grep-open.sh
@@ -53,7 +53,7 @@ test_expect_success SIMPLEPAGER 'git grep -O' '
 	EOF
 	echo grep.h >expect.notless &&
 
-	PATH=.:$PATH git grep -O GREP_PATTERN >out &&
+	PATH=.$PATH_SEP$PATH git grep -O GREP_PATTERN >out &&
 	{
 		test_cmp expect.less pager-args ||
 		test_cmp expect.notless pager-args
diff --git a/t/t9003-help-autocorrect.sh b/t/t9003-help-autocorrect.sh
index f00deaf381..982aac7d16 100755
--- a/t/t9003-help-autocorrect.sh
+++ b/t/t9003-help-autocorrect.sh
@@ -12,7 +12,7 @@ test_expect_success 'setup' '
 		echo distimdistim was called
 	EOF
 
-	PATH="$PATH:." &&
+	PATH="$PATH$PATH_SEP." &&
 	export PATH &&
 
 	git commit --allow-empty -m "a single log entry" &&
diff --git a/t/t9800-git-p4-basic.sh b/t/t9800-git-p4-basic.sh
index dc88d0e064..8a5233e3af 100755
--- a/t/t9800-git-p4-basic.sh
+++ b/t/t9800-git-p4-basic.sh
@@ -286,7 +286,7 @@ test_expect_success 'exit when p4 fails to produce marshaled output' '
 	EOF
 	chmod 755 badp4dir/p4 &&
 	(
-		PATH="$TRASH_DIRECTORY/badp4dir:$PATH" &&
+		PATH="$TRASH_DIRECTORY/badp4dir$PATH_SEP$PATH" &&
 		export PATH &&
 		test_expect_code 1 git p4 clone --dest="$git" //depot >errs 2>&1
 	) &&
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 673ac43456..54cece0290 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -15,6 +15,15 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see http://www.gnu.org/licenses/ .
 
+# On Unix/Linux, the path separator is the colon, on other systems it
+# may be different, though. On Windows, for example, it is a semicolon.
+# If the PATH variable contains semicolons, it is pretty safe to assume
+# that the path separator is a semicolon.
+case "$PATH" in
+*\;*) PATH_SEP=\; ;;
+*) PATH_SEP=: ;;
+esac
+
 # Test the binaries we have just built.  The tests are kept in
 # t/ subdirectory and are run in 'trash directory' subdirectory.
 if test -z "$TEST_DIRECTORY"
@@ -1454,7 +1463,7 @@ then
 		done
 	done
 	IFS=$OLDIFS
-	PATH=$GIT_VALGRIND/bin:$PATH
+	PATH=$GIT_VALGRIND/bin$PATH_SEP$PATH
 	GIT_EXEC_PATH=$GIT_VALGRIND/bin
 	export GIT_VALGRIND
 	GIT_VALGRIND_MODE="$valgrind"
@@ -1466,7 +1475,7 @@ elif test -n "$GIT_TEST_INSTALLED"
 then
 	GIT_EXEC_PATH=$($GIT_TEST_INSTALLED/git --exec-path)  ||
 	error "Cannot run git from $GIT_TEST_INSTALLED."
-	PATH=$GIT_TEST_INSTALLED:$GIT_BUILD_DIR/t/helper:$PATH
+	PATH=$GIT_TEST_INSTALLED$PATH_SEP$GIT_BUILD_DIR/t/helper$PATH_SEP$PATH
 	GIT_EXEC_PATH=${GIT_TEST_EXEC_PATH:-$GIT_EXEC_PATH}
 else # normal case, use ../bin-wrappers only unless $with_dashes:
 	if test -n "$no_bin_wrappers"
@@ -1482,12 +1491,12 @@ else # normal case, use ../bin-wrappers only unless $with_dashes:
 			fi
 			with_dashes=t
 		fi
-		PATH="$git_bin_dir:$PATH"
+		PATH="$git_bin_dir$PATH_SEP$PATH"
 	fi
 	GIT_EXEC_PATH=$GIT_BUILD_DIR
 	if test -n "$with_dashes"
 	then
-		PATH="$GIT_BUILD_DIR:$GIT_BUILD_DIR/t/helper:$PATH"
+		PATH="$GIT_BUILD_DIR$PATH_SEP$GIT_BUILD_DIR/t/helper$PATH_SEP$PATH"
 	fi
 fi
 GIT_TEMPLATE_DIR="$GIT_BUILD_DIR"/templates/blt

From 8bbbae04f16f59315b0d7d17e269d401de87e198 Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Fri, 30 Jun 2017 00:35:40 +0200
Subject: [PATCH 11/20] mingw: only use Bash-ism `builtin pwd -W` when
 available

Traditionally, Git for Windows' SDK uses Bash as its default shell.
However, other Unix shells are available, too. Most notably, the Win32
port of BusyBox comes with `ash` whose `pwd` command already prints
Windows paths as Git for Windows wants them, while there is not even a
`builtin` command.

Therefore, let's be careful not to override `pwd` unless we know that
the `builtin` command is available.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 git-sh-setup.sh | 14 ++++++++++----
 t/test-lib.sh   | 14 ++++++++++----
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/git-sh-setup.sh b/git-sh-setup.sh
index 785a4cbfa9..b53539cd0e 100644
--- a/git-sh-setup.sh
+++ b/git-sh-setup.sh
@@ -306,10 +306,16 @@ case $(uname -s) in
 			/usr/bin/find "$@"
 		}
 	fi
-	# git sees Windows-style pwd
-	pwd () {
-		builtin pwd -W
-	}
+	# On Windows, Git wants Windows paths. But /usr/bin/pwd spits out
+	# Unix-style paths. At least in Bash, we have a builtin pwd that
+	# understands the -W option to force "mixed" paths, i.e. with drive
+	# prefix but still with forward slashes. Let's use that, if available.
+	if type builtin >/dev/null 2>&1
+	then
+		pwd () {
+			builtin pwd -W
+		}
+	fi
 	is_absolute_path () {
 		case "$1" in
 		[/\\]* | [A-Za-z]:*)
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 54cece0290..d804c230de 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1720,10 +1720,16 @@ case $uname_s in
 			/usr/bin/find "$@"
 		}
 	fi
-	# git sees Windows-style pwd
-	pwd () {
-		builtin pwd -W
-	}
+	# On Windows, Git wants Windows paths. But /usr/bin/pwd spits out
+	# Unix-style paths. At least in Bash, we have a builtin pwd that
+	# understands the -W option to force "mixed" paths, i.e. with drive
+	# prefix but still with forward slashes. Let's use that, if available.
+	if type builtin >/dev/null 2>&1
+	then
+		pwd () {
+			builtin pwd -W
+		}
+	fi
 	# no POSIX permissions
 	# backslashes in pathspec are converted to '/'
 	# exec does not inherit the PID

From c09de2dce0e1507d978fa72813a8735998f6446e Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Fri, 30 Jun 2017 22:32:33 +0200
Subject: [PATCH 12/20] tests (mingw): remove Bash-specific pwd option

The -W option is only understood by MSYS2 Bash's pwd command. We already
make sure to override `pwd` by `builtin pwd -W` for MINGW, so let's not
double the effort here.

This will also help when switching the shell to another one (such as
BusyBox' ash) whose pwd does *not* understand the -W option.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 t/t9902-completion.sh | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/t/t9902-completion.sh b/t/t9902-completion.sh
index 43de868b80..d1e93f9529 100755
--- a/t/t9902-completion.sh
+++ b/t/t9902-completion.sh
@@ -126,12 +126,7 @@ invalid_variable_name='${foo.bar}'
 
 actual="$TRASH_DIRECTORY/actual"
 
-if test_have_prereq MINGW
-then
-	ROOT="$(pwd -W)"
-else
-	ROOT="$(pwd)"
-fi
+ROOT="$(pwd)"
 
 test_expect_success 'setup for __git_find_repo_path/__gitdir tests' '
 	mkdir -p subdir/subsubdir &&

From a9b106df99303b62696bdd35e39826c509306bfd Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Wed, 19 Jul 2017 17:07:56 +0200
Subject: [PATCH 13/20] test-lib: add BUSYBOX prerequisite

When running with BusyBox, we will want to avoid calling executables on
the PATH that are implemented in BusyBox itself.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 t/test-lib.sh | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/t/test-lib.sh b/t/test-lib.sh
index d804c230de..0ea917ab51 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1902,6 +1902,10 @@ test_lazy_prereq UNZIP '
 	test $? -ne 127
 '
 
+test_lazy_prereq BUSYBOX '
+	case "$($SHELL --help 2>&1)" in *BusyBox*) true;; *) false;; esac
+'
+
 run_with_limited_cmdline () {
 	(ulimit -s 128 && "$@")
 }

From d381dd1fa7848b0f649fa659cd6f7f583670e601 Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Fri, 4 Aug 2017 11:51:56 +0200
Subject: [PATCH 14/20] t0021: use Windows path when appropriate

Since c6b0831c9c1 (docs: warn about possible '=' in clean/smudge filter
process values, 2016-12-03), t0021 writes out a file with quotes in its
name, and MSYS2's path conversion heuristics mistakes that to mean that
we are not talking about a path here.

Therefore, we need to use Windows paths, as the test-helper is a Win32
program that would otherwise have no idea where to look for the file.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 t/t0021-conversion.sh | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/t/t0021-conversion.sh b/t/t0021-conversion.sh
index c8560d57cb..408aeededc 100755
--- a/t/t0021-conversion.sh
+++ b/t/t0021-conversion.sh
@@ -8,8 +8,8 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-terminal.sh
 
-TEST_ROOT="$PWD"
-PATH=$TEST_ROOT$PATH_SEP$PATH
+TEST_ROOT="$(pwd)"
+PATH=$PWD$PATH_SEP$PATH
 
 write_script <<\EOF "$TEST_ROOT/rot13.sh"
 tr \

From 1244d12982d7fa6278845244284f578d2254524a Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Sat, 5 Aug 2017 21:36:01 +0200
Subject: [PATCH 15/20] t5003: use binary file from t/lib-diff/

At some stage, t5003-archive-zip wants to add a file that is not ASCII.
To that end, it uses /bin/sh. But that file may actually not exist (it
is too easy to forget that not all the world is Unix/Linux...)! Besides,
we already have perfectly fine binary files intended for use solely by
the tests. So let's use one of them instead.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 t/t5003-archive-zip.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/t/t5003-archive-zip.sh b/t/t5003-archive-zip.sh
index fc499cdff0..2bfa0c0a28 100755
--- a/t/t5003-archive-zip.sh
+++ b/t/t5003-archive-zip.sh
@@ -88,7 +88,7 @@ test_expect_success \
     'mkdir a &&
      echo simple textfile >a/a &&
      mkdir a/bin &&
-     cp /bin/sh a/bin &&
+     cp "$TEST_DIRECTORY/lib-diff/test-binary-1.png" a/bin &&
      printf "text\r"	>a/text.cr &&
      printf "text\r\n"	>a/text.crlf &&
      printf "text\n"	>a/text.lf &&

From feacae5b441433ac9a5ab6fa01f5a59f7db3888f Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Fri, 21 Jul 2017 12:48:33 +0200
Subject: [PATCH 16/20] t5532: workaround for BusyBox on Windows

While it may seem super convenient to some old Unix hands to simpy
require Perl to be available when running the test suite, this is a
major hassle on Windows, where we want to verify that Perl is not,
actually, required in a NO_PERL build.

As a super ugly workaround, we "install" a script into /usr/bin/perl
reading like this:

	#!/bin/sh

	# We'd much rather avoid requiring Perl altogether when testing
	# an installed Git. Oh well, that's why we cannot have nice
	# things.
	exec c:/git-sdk-64/usr/bin/perl.exe "$@"

The problem with that is that BusyBox assumes that the #! line in a
script refers to an executable, not to a script. So when it encounters
the line #!/usr/bin/perl in t5532's proxy-get-cmd, it barfs.

Let's help this situation by simply executing the Perl script with the
"interpreter" specified explicitly.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 t/t5532-fetch-proxy.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/t/t5532-fetch-proxy.sh b/t/t5532-fetch-proxy.sh
index d664912799..55bc57c138 100755
--- a/t/t5532-fetch-proxy.sh
+++ b/t/t5532-fetch-proxy.sh
@@ -27,7 +27,7 @@ test_expect_success 'setup proxy script' '
 
 	write_script proxy <<-\EOF
 	echo >&2 "proxying for $*"
-	cmd=$(./proxy-get-cmd)
+	cmd=$("$PERL_PATH" ./proxy-get-cmd)
 	echo >&2 "Running $cmd"
 	exec $cmd
 	EOF

From 6798066380f4dfda1d0de8d9039ee18d21d75eb4 Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Fri, 21 Jul 2017 13:24:55 +0200
Subject: [PATCH 17/20] t5605: special-case hardlink test for BusyBox-w32

When t5605 tries to verify that files are hardlinked (or that they are
not), it uses the `-links` option of the `find` utility.

BusyBox' implementation does not support that option, and BusyBox-w32's
lstat() does not even report the number of hard links correctly (for
performance reasons).

So let's just switch to a different method that actually works on
Windows.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 t/t5605-clone-local.sh | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/t/t5605-clone-local.sh b/t/t5605-clone-local.sh
index 38b850c10e..829d54edc0 100755
--- a/t/t5605-clone-local.sh
+++ b/t/t5605-clone-local.sh
@@ -11,6 +11,21 @@ repo_is_hardlinked() {
 	test_line_count = 0 output
 }
 
+if test_have_prereq MINGW,BUSYBOX
+then
+	# BusyBox' `find` does not support `-links`. Besides, BusyBox-w32's
+	# lstat() does not report hard links, just like Git's mingw_lstat()
+	# (from where BusyBox-w32 got its initial implementation).
+	repo_is_hardlinked() {
+		for f in $(find "$1/objects" -type f)
+		do
+			"$SYSTEMROOT"/system32/fsutil.exe \
+				hardlink list $f >links &&
+			test_line_count -gt 1 links || return 1
+		done
+	}
+fi
+
 test_expect_success 'preparing origin repository' '
 	: >file && git add . && git commit -m1 &&
 	git clone --bare . a.git &&

From 84b2eebbf278ea5a3695feabb36a7273f96ae3c2 Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Wed, 5 Jul 2017 15:14:50 +0200
Subject: [PATCH 18/20] t5813: allow for $PWD to be a Windows path

Git for Windows uses MSYS2's Bash to run the test suite, which comes
with benefits but also at a heavy price: on the plus side, MSYS2's
POSIX emulation layer allows us to continue pretending that we are on a
Unix system, e.g. use Unix paths instead of Windows ones, yet this is
bought at a rather noticeable performance penalty.

There *are* some more native ports of Unix shells out there, though,
most notably BusyBox-w32's ash. These native ports do not use any POSIX
emulation layer (or at most a *very* thin one, choosing to avoid
features such as fork() that are expensive to emulate on Windows), and
they use native Windows paths (usually with forward slashes instead of
backslashes, which is perfectly legal in almost all use cases).

And here comes the problem: with a $PWD looking like, say,
C:/git-sdk-64/usr/src/git/t/trash directory.t5813-proto-disable-ssh
Git's test scripts get quite a bit confused, as their assumptions have
been shattered. Not only does this path contain a colon (oh no!), it
also does not start with a slash.

This is a problem e.g. when constructing a URL as t5813 does it:
ssh://remote$PWD. Not only is it impossible to separate the "host" from
the path with a $PWD as above, even prefixing $PWD by a slash won't
work, as /C:/git-sdk-64/... is not a valid path.

As a workaround, detect when $PWD does not start with a slash on
Windows, and simply strip the drive prefix, using an obscure feature of
Windows paths: if an absolute Windows path starts with a slash, it is
implicitly prefixed by the drive prefix of the current directory. As we
are talking about the current directory here, anyway, that strategy
works.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 t/t5813-proto-disable-ssh.sh | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/t/t5813-proto-disable-ssh.sh b/t/t5813-proto-disable-ssh.sh
index 3f084ee306..0a2c77093b 100755
--- a/t/t5813-proto-disable-ssh.sh
+++ b/t/t5813-proto-disable-ssh.sh
@@ -14,8 +14,23 @@ test_expect_success 'setup repository to clone' '
 '
 
 test_proto "host:path" ssh "remote:repo.git"
-test_proto "ssh://" ssh "ssh://remote$PWD/remote/repo.git"
-test_proto "git+ssh://" ssh "git+ssh://remote$PWD/remote/repo.git"
+
+hostdir="$PWD"
+if test_have_prereq MINGW && test "/${PWD#/}" != "$PWD"
+then
+	case "$PWD" in
+	[A-Za-z]:/*)
+		hostdir="${PWD#?:}"
+		;;
+	*)
+		skip_all="Unhandled PWD '$PWD'; skipping rest"
+		test_done
+		;;
+	esac
+fi
+
+test_proto "ssh://" ssh "ssh://remote$hostdir/remote/repo.git"
+test_proto "git+ssh://" ssh "git+ssh://remote$hostdir/remote/repo.git"
 
 # Don't even bother setting up a "-remote" directory, as ssh would generally
 # complain about the bogus option rather than completing our request. Our

From 5b31f7f2af277dc511dc4b426b12bb869260517b Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Fri, 7 Jul 2017 10:15:36 +0200
Subject: [PATCH 19/20] t9200: skip tests when $PWD contains a colon

On Windows, the current working directory is pretty much guaranteed to
contain a colon. If we feed that path to CVS, it mistakes it for a
separator between host and port, though.

This has not been a problem so far because Git for Windows uses MSYS2's
Bash using a POSIX emulation layer that also pretends that the current
directory is a Unix path (at least as long as we're in a shell script).

However, that is rather limiting, as Git for Windows also explores other
ports of other Unix shells. One of those is BusyBox-w32's ash, which is
a native port (i.e. *not* using any POSIX emulation layer, and certainly
not emulating Unix paths).

So let's just detect if there is a colon in $PWD and punt in that case.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 t/t9200-git-cvsexportcommit.sh | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/t/t9200-git-cvsexportcommit.sh b/t/t9200-git-cvsexportcommit.sh
index 3e1034e6b4..450ff1c2bc 100755
--- a/t/t9200-git-cvsexportcommit.sh
+++ b/t/t9200-git-cvsexportcommit.sh
@@ -11,6 +11,13 @@ if ! test_have_prereq PERL; then
 	test_done
 fi
 
+case "$PWD" in
+*:*)
+	skip_all='cvs would get confused by the colon in `pwd`; skipping tests'
+	test_done
+	;;
+esac
+
 cvs >/dev/null 2>&1
 if test $? -ne 1
 then

From 7364463f8605d4d38eaa2738ceeb8a1c74e0f56b Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Thu, 20 Jul 2017 00:23:26 +0200
Subject: [PATCH 20/20] mingw: add a Makefile target to copy test artifacts

The Makefile target `install-mingit-test-artifacts` simply copies stuff
and things directly into a MinGit directory, including an init.bat
script to set everything up so that the tests can be run in a cmd
window.

Sadly, Git's test suite still relies on a Perl interpreter even if
compiled with NO_PERL=YesPlease. We punt for now, installing a small
script into /usr/bin/perl that hands off to an existing Perl of a Git
for Windows SDK.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 config.mak.uname | 56 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)

diff --git a/config.mak.uname b/config.mak.uname
index 784d1691c1..307ec88e2d 100644
--- a/config.mak.uname
+++ b/config.mak.uname
@@ -740,6 +740,62 @@ else
 		NO_PYTHON = YesPlease
 	endif
 endif
+ifeq (i686,$(uname_M))
+	MINGW_PREFIX := mingw32
+endif
+ifeq (x86_64,$(uname_M))
+	MINGW_PREFIX := mingw64
+endif
+
+	DESTDIR_WINDOWS = $(shell cygpath -aw '$(DESTDIR_SQ)')
+	DESTDIR_MIXED = $(shell cygpath -am '$(DESTDIR_SQ)')
+install-mingit-test-artifacts:
+	install -m755 -d '$(DESTDIR_SQ)/usr/bin'
+	printf '%s\n%s\n' >'$(DESTDIR_SQ)/usr/bin/perl' \
+		"#!/mingw64/bin/busybox sh" \
+		"exec \"$(shell cygpath -am /usr/bin/perl.exe)\" \"\$$@\""
+
+	install -m755 -d '$(DESTDIR_SQ)'
+	printf '%s%s\n%s\n%s\n%s\n%s\n' >'$(DESTDIR_SQ)/init.bat' \
+		"PATH=$(DESTDIR_WINDOWS)\\$(MINGW_PREFIX)\\bin;" \
+		"C:\\WINDOWS;C:\\WINDOWS\\system32" \
+		"@set GIT_TEST_INSTALLED=$(DESTDIR_MIXED)/$(MINGW_PREFIX)/bin" \
+		"@`echo "$(DESTDIR_WINDOWS)" | sed 's/:.*/:/'`" \
+		"@cd `echo "$(DESTDIR_WINDOWS)" | sed 's/^.://'`\\test-git\\t" \
+		"@echo Now, run 'helper\\test-run-command testsuite'"
+
+	install -m755 -d '$(DESTDIR_SQ)/test-git'
+	sed 's/^\(NO_PERL\|NO_PYTHON\)=.*/\1=YesPlease/' \
+		<GIT-BUILD-OPTIONS >'$(DESTDIR_SQ)/test-git/GIT-BUILD-OPTIONS'
+
+	install -m755 -d '$(DESTDIR_SQ)/test-git/t/helper'
+	install -m755 $(TEST_PROGRAMS) '$(DESTDIR_SQ)/test-git/t/helper'
+	(cd t && $(TAR) cf - t[0-9][0-9][0-9][0-9] lib-diff) | \
+	(cd '$(DESTDIR_SQ)/test-git/t' && $(TAR) xf -)
+	install -m755 t/t556x_common t/*.sh '$(DESTDIR_SQ)/test-git/t'
+
+	install -m755 -d '$(DESTDIR_SQ)/test-git/templates'
+	(cd templates && $(TAR) cf - blt) | \
+	(cd '$(DESTDIR_SQ)/test-git/templates' && $(TAR) xf -)
+
+	# po/build/locale for t0200
+	install -m755 -d '$(DESTDIR_SQ)/test-git/po/build/locale'
+	(cd po/build/locale && $(TAR) cf - .) | \
+	(cd '$(DESTDIR_SQ)/test-git/po/build/locale' && $(TAR) xf -)
+
+	# git-daemon.exe for t5802, git-http-backend.exe for t5560
+	install -m755 -d '$(DESTDIR_SQ)/$(MINGW_PREFIX)/bin'
+	install -m755 git-daemon.exe git-http-backend.exe \
+		'$(DESTDIR_SQ)/$(MINGW_PREFIX)/bin'
+
+	# git-upload-archive (dashed) for t5000
+	install -m755 -d '$(DESTDIR_SQ)/$(MINGW_PREFIX)/bin'
+	install -m755 git-upload-archive.exe '$(DESTDIR_SQ)/$(MINGW_PREFIX)/bin'
+
+	# git-difftool--helper for t7800
+	install -m755 -d '$(DESTDIR_SQ)/$(MINGW_PREFIX)/libexec/git-core'
+	install -m755 git-difftool--helper \
+		'$(DESTDIR_SQ)/$(MINGW_PREFIX)/libexec/git-core'
 endif
 ifeq ($(uname_S),QNX)
 	COMPAT_CFLAGS += -DSA_RESTART=0