Merge branch 'jk/repo-info-path-keys' into jch

The "git repo info" command has been taught new keys to output both
absolute and relative paths for "gitdir" and "commondir", supported by
a new path-formatting helper extracted from "git rev-parse".

* jk/repo-info-path-keys:
  repo: add path.gitdir with absolute and relative suffix formatting
  repo: add path.commondir with absolute and relative suffix formatting
  path: extract format_path() and use in rev-parse

Documentation/git-repo.adoc

@@ -104,6 +104,21 @@ values that they return:
 `object.format`::
 	The object format (hash algorithm) used in the repository.
 
+`path.commondir.absolute`::
+	The canonical absolute path to the Git repository's common
+	directory (the shared `.git` directory containing objects,
+	refs, and global configuration).
+
+`path.commondir.relative`::
+	The path to the Git repository's common directory relative to
+	the current working directory.
+
+`path.gitdir.absolute`::
+	The canonical absolute path to the Git repository directory (the `.git` directory).
+
+`path.gitdir.relative`::
+	The path to the Git repository directory relative to the current working directory.
+
 `references.format`::
 	The reference storage format. The valid values are:
 +

builtin/repo.c

@@ -7,12 +7,14 @@
 #include "hex.h"
 #include "odb.h"
 #include "parse-options.h"
+#include "path.h"
 #include "path-walk.h"
 #include "progress.h"
 #include "quote.h"
 #include "ref-filter.h"
 #include "refs.h"
 #include "revision.h"
+#include "setup.h"
 #include "strbuf.h"
 #include "string-list.h"
 #include "shallow.h"
@@ -75,6 +77,50 @@ static int get_object_format(struct repository *repo, struct strbuf *buf)
 	return 0;
 }
 
+static int get_path_commondir_absolute(struct repository *repo, struct strbuf *buf)
+{
+	const char *common_dir = repo_get_common_dir(repo);
+
+	if (!common_dir)
+		return error(_("unable to get common directory"));
+
+	format_path(buf, common_dir, startup_info->prefix, PATH_FORMAT_CANONICAL);
+	return 0;
+}
+
+static int get_path_commondir_relative(struct repository *repo, struct strbuf *buf)
+{
+	const char *common_dir = repo_get_common_dir(repo);
+
+	if (!common_dir)
+		return error(_("unable to get common directory"));
+
+	format_path(buf, common_dir, startup_info->prefix, PATH_FORMAT_RELATIVE);
+	return 0;
+}
+
+static int get_path_gitdir_absolute(struct repository *repo, struct strbuf *buf)
+{
+	const char *git_dir = repo_get_git_dir(repo);
+
+	if (!git_dir)
+		return error(_("unable to get git directory"));
+
+	format_path(buf, git_dir, startup_info->prefix, PATH_FORMAT_CANONICAL);
+	return 0;
+}
+
+static int get_path_gitdir_relative(struct repository *repo, struct strbuf *buf)
+{
+	const char *git_dir = repo_get_git_dir(repo);
+
+	if (!git_dir)
+		return error(_("unable to get git directory"));
+
+	format_path(buf, git_dir, startup_info->prefix, PATH_FORMAT_RELATIVE);
+	return 0;
+}
+
 static int get_references_format(struct repository *repo, struct strbuf *buf)
 {
 	strbuf_addstr(buf,
@@ -87,6 +133,10 @@ static const struct repo_info_field repo_info_field[] = {
 	{ "layout.bare", get_layout_bare },
 	{ "layout.shallow", get_layout_shallow },
 	{ "object.format", get_object_format },
+	{ "path.commondir.absolute", get_path_commondir_absolute },
+	{ "path.commondir.relative", get_path_commondir_relative },
+	{ "path.gitdir.absolute", get_path_gitdir_absolute },
+	{ "path.gitdir.relative", get_path_gitdir_relative },
 	{ "references.format", get_references_format },
 };
 

builtin/rev-parse.c

@@ -653,53 +653,46 @@ enum default_type {
 	DEFAULT_UNMODIFIED,
 };
 
-static void print_path(const char *path, const char *prefix, enum format_type format, enum default_type def)
+static void print_path(const char *path, const char *prefix,
+		       enum format_type format, enum default_type def)
 {
-	char *cwd = NULL;
-	/*
-	 * We don't ever produce a relative path if prefix is NULL, so set the
-	 * prefix to the current directory so that we can produce a relative
-	 * path whenever possible.  If we're using RELATIVE_IF_SHARED mode, then
-	 * we want an absolute path unless the two share a common prefix, so don't
-	 * set it in that case, since doing so causes a relative path to always
-	 * be produced if possible.
-	 */
-	if (!prefix && (format != FORMAT_DEFAULT || def != DEFAULT_RELATIVE_IF_SHARED))
-		prefix = cwd = xgetcwd();
-	if (format == FORMAT_DEFAULT && def == DEFAULT_UNMODIFIED) {
-		puts(path);
-	} else if (format == FORMAT_RELATIVE ||
-		  (format == FORMAT_DEFAULT && def == DEFAULT_RELATIVE)) {
-		/*
-		 * In order for relative_path to work as expected, we need to
-		 * make sure that both paths are absolute paths.  If we don't,
-		 * we can end up with an unexpected absolute path that the user
-		 * didn't want.
-		 */
-		struct strbuf buf = STRBUF_INIT, realbuf = STRBUF_INIT, prefixbuf = STRBUF_INIT;
-		if (!is_absolute_path(path)) {
-			strbuf_realpath_forgiving(&realbuf, path,  1);
-			path = realbuf.buf;
+	struct strbuf sb = STRBUF_INIT;
+	enum path_format fmt;
+
+	if (format == FORMAT_DEFAULT) {
+		switch (def) {
+		case DEFAULT_RELATIVE:
+			fmt = PATH_FORMAT_RELATIVE;
+			break;
+		case DEFAULT_RELATIVE_IF_SHARED:
+			fmt = PATH_FORMAT_RELATIVE_IF_SHARED;
+			break;
+		case DEFAULT_CANONICAL:
+			fmt = PATH_FORMAT_CANONICAL;
+			break;
+		case DEFAULT_UNMODIFIED:
+		default:
+			fmt = PATH_FORMAT_UNMODIFIED;
+			break;
 		}
-		if (!is_absolute_path(prefix)) {
-			strbuf_realpath_forgiving(&prefixbuf, prefix, 1);
-			prefix = prefixbuf.buf;
-		}
-		puts(relative_path(path, prefix, &buf));
-		strbuf_release(&buf);
-		strbuf_release(&realbuf);
-		strbuf_release(&prefixbuf);
-	} else if (format == FORMAT_DEFAULT && def == DEFAULT_RELATIVE_IF_SHARED) {
-		struct strbuf buf = STRBUF_INIT;
-		puts(relative_path(path, prefix, &buf));
-		strbuf_release(&buf);
 	} else {
-		struct strbuf buf = STRBUF_INIT;
-		strbuf_realpath_forgiving(&buf, path, 1);
-		puts(buf.buf);
-		strbuf_release(&buf);
+		switch (format) {
+		case FORMAT_RELATIVE:
+			fmt = PATH_FORMAT_RELATIVE;
+			break;
+		case FORMAT_CANONICAL:
+			fmt = PATH_FORMAT_CANONICAL;
+			break;
+		default:
+			fmt = PATH_FORMAT_UNMODIFIED;
+			break;
+		}
 	}
-	free(cwd);
+
+	format_path(&sb, path, prefix, fmt);
+	puts(sb.buf);
+
+	strbuf_release(&sb);
 }
 
 int cmd_rev_parse(int argc,

path.c

@@ -1579,6 +1579,75 @@ char *xdg_cache_home(const char *filename)
 	return NULL;
 }
 
+void format_path(struct strbuf *dest, const char *path,
+		 const char *prefix, enum path_format format)
+{
+	strbuf_reset(dest);
+
+	switch (format) {
+	case PATH_FORMAT_UNMODIFIED:
+		strbuf_addstr(dest, path);
+		break;
+
+	case PATH_FORMAT_RELATIVE: {
+		struct strbuf relative_buf = STRBUF_INIT;
+		struct strbuf real_path = STRBUF_INIT;
+		struct strbuf real_prefix = STRBUF_INIT;
+		char *cwd = NULL;
+
+		/*
+		 * We don't ever produce a relative path if prefix is NULL,
+		 * so set the prefix to the current directory so that we can
+		 * produce a relative path whenever possible.
+		 */
+		if (!prefix)
+			prefix = cwd = xgetcwd();
+
+		if (!is_absolute_path(path)) {
+			strbuf_realpath_forgiving(&real_path, path, 1);
+			path = real_path.buf;
+		}
+		if (!is_absolute_path(prefix)) {
+			strbuf_realpath_forgiving(&real_prefix, prefix, 1);
+			prefix = real_prefix.buf;
+		}
+
+		strbuf_addstr(dest, relative_path(path, prefix, &relative_buf));
+
+		strbuf_release(&relative_buf);
+		strbuf_release(&real_path);
+		strbuf_release(&real_prefix);
+		free(cwd);
+		break;
+	}
+
+	case PATH_FORMAT_RELATIVE_IF_SHARED: {
+		struct strbuf relative_buf = STRBUF_INIT;
+
+		/*
+		 * If we're using RELATIVE_IF_SHARED mode, then we want an
+		 * absolute path unless the two share a common prefix, so don't
+		 * default the prefix to the current working directory. Doing so
+		 * would cause a relative path to always be produced if possible.
+		 */
+		strbuf_addstr(dest, relative_path(path, prefix, &relative_buf));
+		strbuf_release(&relative_buf);
+		break;
+	}
+
+	case PATH_FORMAT_CANONICAL:
+		/*
+		 * strbuf_realpath_forgiving inherently resets the destination
+		 * buffer, safely aligning with our replace semantics.
+		 */
+		strbuf_realpath_forgiving(dest, path, 1);
+		break;
+
+	default:
+		BUG("unknown path_format value %d", format);
+	}
+}
+
 REPO_GIT_PATH_FUNC(squash_msg, "SQUASH_MSG")
 REPO_GIT_PATH_FUNC(merge_msg, "MERGE_MSG")
 REPO_GIT_PATH_FUNC(merge_rr, "MERGE_RR")

path.h

@@ -262,6 +262,36 @@ enum scld_error safe_create_leading_directories_no_share(char *path);
 int safe_create_file_with_leading_directories(struct repository *repo,
 					      const char *path);
 
+/**
+ * The formatting strategy to apply when writing a path into a buffer.
+ */
+enum path_format {
+	/* Output the path exactly as-is without any modifications. */
+	PATH_FORMAT_UNMODIFIED,
+
+	/* Output a path relative to the provided directory prefix. */
+	PATH_FORMAT_RELATIVE,
+
+	/* Output a relative path only if the path shares a root with the prefix. */
+	PATH_FORMAT_RELATIVE_IF_SHARED,
+
+	/* Output a fully resolved, absolute canonical path. */
+	PATH_FORMAT_CANONICAL
+};
+
+/**
+ * Format a path according to the specified formatting strategy and store
+ * the result in the given strbuf, replacing any existing contents.
+ *
+ * `dest`   : The string buffer to store the formatted path into.
+ * `path`   : The path string that needs to be formatted.
+ * `prefix` : The directory prefix to calculate relative offsets against.
+ * Pass NULL to default to the current working directory where applicable.
+ * `format` : The formatting behavior rule to execute.
+ */
+void format_path(struct strbuf *dest, const char *path,
+		 const char *prefix, enum path_format format);
+
 # ifdef USE_THE_REPOSITORY_VARIABLE
 #  include "strbuf.h"
 #  include "repository.h"

t/t1900-repo-info.sh

@@ -155,4 +155,62 @@ test_expect_success 'git repo info -h shows only repo info usage' '
 	test_grep ! "git repo structure" actual
 '
 
+# Helper function to test path keys in both absolute and relative formats.
+# $1: label for the test
+# $2: field_name (e.g., commondir)
+# $3: expected_dir (the directory name, e.g., .git or custom-common)
+# $4: init_command (extra setup like exporting env vars)
+test_repo_info_path () {
+	label=$1
+	field_name=$2
+	expected_dir=$3
+	init_command=$4
+
+	test_expect_success "absolute: $label" '
+		test_when_finished "rm -rf repo" &&
+		git init repo &&
+		(
+			mkdir -p repo/sub &&
+			cd repo/sub &&
+			ROOT="$(test-tool path-utils real_path ..)" && export ROOT &&
+			eval "$init_command" &&
+			echo "path.$field_name.absolute=$ROOT/$expected_dir" >expect &&
+			git repo info "path.$field_name.absolute" >actual &&
+			test_cmp expect actual
+		)
+	'
+
+	test_expect_success "relative: $label" '
+		test_when_finished "rm -rf repo" &&
+		git init repo &&
+		(
+			mkdir -p repo/sub &&
+			cd repo/sub &&
+			ROOT="$(test-tool path-utils real_path ..)" && export ROOT &&
+			eval "$init_command" &&
+			echo "path.$field_name.relative=../$expected_dir" >expect &&
+			git repo info "path.$field_name.relative" >actual &&
+			test_cmp expect actual
+		)
+	'
+}
+
+test_repo_info_path 'commondir standard' 'commondir' '.git'
+
+test_repo_info_path 'commondir with GIT_COMMON_DIR and GIT_DIR' 'commondir' \
+	'custom-common' \
+	'GIT_COMMON_DIR="$ROOT/custom-common" && export GIT_COMMON_DIR &&
+	 GIT_DIR="../.git" && export GIT_DIR &&
+	 git init --bare "$ROOT/custom-common"'
+
+test_repo_info_path 'commondir with only GIT_DIR' 'commondir' \
+	'.git' \
+	'GIT_DIR="../.git" && export GIT_DIR'
+
+test_repo_info_path 'gitdir standard' 'gitdir' '.git'
+
+test_repo_info_path 'gitdir with explicit GIT_DIR' 'gitdir' \
+	'.git' \
+	'GIT_DIR="../.git" && export GIT_DIR'
+
 test_done