t: convert grep assertions to test_grep

Replace bare grep with test_grep in test assertions across the
suite, including sourced test helpers (lib-*.sh, *-tests.sh).
test_grep prints the contents of the file being searched on
failure, making debugging easier than a bare grep which fails
silently.

Only assertion-style greps are converted: grep used as a filter
in pipelines, command substitutions, conditionals, or with
redirected I/O is left as-is with a "# lint-ok" annotation.
Existing '! test_grep' calls are rewritten to 'test_grep !' so
that the diagnostic output is preserved on failure.

The conversion was generated using a grep-assertion linter
(greplint.pl, added in the following commit) to identify bare
grep calls at command position.  To reproduce:

    # Step 1: mark bare greps that should not be converted
    sed -i '/! grep "$m" \.git\/packed-refs/s/$/ # lint-ok: file may not exist (reftable)/' \
        t/t1400-update-ref.sh
    sed -i '/! grep dirty file3 &&/{/lint-ok/!s/$/ # lint-ok: file may not exist after --quit/}' \
        t/t3420-rebase-autostash.sh
    sed -i '/grep -vf before commits\.raw/s/$/ # lint-ok: data filter/' \
        t/t5326-multi-pack-bitmaps.sh
    sed -i '/! grep $d shallow-client\/\.git\/shallow/s/$/ # lint-ok: file may not exist after repack/' \
        t/t5537-fetch-shallow.sh
    sed -i '/grep -E "^\[0-9a-f\].*|| :/s/$/ # lint-ok: data filter/' \
        t/t5702-protocol-v2.sh
    sed -i '/! grep gitdir squatting-clone/s/$/ # lint-ok: file may not exist after failed clone/' \
        t/t7450-bad-git-dotfiles.sh

    # Step 2: reorder pre-existing '! test_grep' to 'test_grep !'
    # (must come before steps 3-4 so greplint does not see them)
    sed -i 's/! test_grep/test_grep !/' t/t0031-lockfile-pid.sh
    sed -i 's/! test_grep/test_grep !/' t/t5300-pack-object.sh
    sed -i 's/! test_grep/test_grep !/' t/t5319-multi-pack-index.sh

    # Step 3: convert '! grep' -> 'test_grep !'
    perl t/greplint.pl t/*.sh 2>&1 | cut -d: -f1,2 |
    while IFS=: read f l; do
        sed -i "${l}s/! *grep/test_grep !/" "$f"
    done

    # Step 4: convert remaining 'grep' -> 'test_grep'
    perl t/greplint.pl t/*.sh 2>&1 | cut -d: -f1,2 |
    while IFS=: read f l; do
        sed -i "${l}s/grep/test_grep/" "$f"
    done

To verify, run: make -C t test-greplint

Signed-off-by: Michael Montalbo <mmontalbo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t7501-commit-basic-functionality.sh

@@ -342,12 +342,12 @@ test_expect_success 'overriding author from command line' '
 	echo gak >file &&
 	git commit -m author \
 		--author "Rubber Duck <rduck@convoy.org>" -a >output 2>&1 &&
-	grep Rubber.Duck output
+	test_grep Rubber.Duck output
 '
 
 test_expect_success 'interactive add' '
 	echo 7 | test_must_fail git commit --interactive >out &&
-	grep "What now" out
+	test_grep "What now" out
 '
 
 test_expect_success "commit --interactive doesn't change index if editor aborts" '
@@ -376,13 +376,13 @@ test_expect_success 'editor not invoked if -F is given' '
 
 	EDITOR=./editor git commit -a -F msg &&
 	git show -s --pretty=format:%s >subject &&
-	grep -q good subject &&
+	test_grep -q good subject &&
 
 	echo quack >file &&
 	echo Another good message. |
 	EDITOR=./editor git commit -a -F - &&
 	git show -s --pretty=format:%s >subject &&
-	grep -q good subject
+	test_grep -q good subject
 '
 
 test_expect_success 'partial commit that involves removal (1)' '
@@ -471,7 +471,7 @@ test_expect_success 'amend does not add signoff if it already exists' '
 
 test_expect_success 'commit mentions forced date in output' '
 	git commit --amend --date=2010-01-02T03:04:05 >output &&
-	grep "Date: *Sat Jan 2 03:04:05 2010" output
+	test_grep "Date: *Sat Jan 2 03:04:05 2010" output
 '
 
 test_expect_success 'commit complains about completely bogus dates' '
@@ -660,9 +660,9 @@ test_expect_success 'git commit <file> with dirty index' '
 	git add chz &&
 	git commit elif -m "tacocat is a palindrome" &&
 	git show --stat >stat &&
-	grep elif stat &&
+	test_grep elif stat &&
 	git diff --cached >diff &&
-	grep chz diff
+	test_grep chz diff
 '
 
 test_expect_success 'same tree (single parent)' '
@@ -676,7 +676,7 @@ test_expect_success 'same tree (single parent) --allow-empty' '
 
 	git commit --allow-empty -m "forced empty" &&
 	git cat-file commit HEAD >commit &&
-	grep forced commit
+	test_grep forced commit
 
 '