restore legacy behavior for read_sha1_file()

Since commit 8eca0b47ff1598a6d163df9358c0e0c9bd92d4c8, it is possible
for read_sha1_file() to return NULL even with existing objects when they
are corrupted.  Previously a corrupted object would have terminated the
program immediately, effectively making read_sha1_file() return NULL
only when specified object is not found.

Let's restore this behavior for all users of read_sha1_file() and
provide a separate function with the ability to not terminate when
bad objects are encountered.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 60 insertions, 0 deletions

diff --git a/t/t6011-rev-list-with-bad-commit.sh b/t/t6011-rev-list-with-bad-commit.sh
new file mode 100755
index 0000000000..e51eb41f4b
--- /dev/null
+++ b/t/t6011-rev-list-with-bad-commit.sh
@@ -0,0 +1,60 @@
+#!/bin/sh
+
+test_description='git rev-list should notice bad commits'
+
+. ./test-lib.sh
+
+# Note:
+# - compression level is set to zero to make "corruptions" easier to perform
+# - reflog is disabled to avoid extra references which would twart the test
+
+test_expect_success 'setup' \
+   '
+   git init &&
+   git config core.compression 0 &&
+   git config core.logallrefupdates false &&
+   echo "foo" > foo &&
+   git add foo &&
+   git commit -m "first commit" &&
+   echo "bar" > bar &&
+   git add bar &&
+   git commit -m "second commit" &&
+   echo "baz" > baz &&
+   git add baz &&
+   git commit -m "third commit" &&
+   echo "foo again" >> foo &&
+   git add foo &&
+   git commit -m "fourth commit" &&
+   git repack -a -f -d
+   '
+
+test_expect_success 'verify number of revisions' \
+   '
+   revs=$(git rev-list --all | wc -l) &&
+   test $revs -eq 4 &&
+   first_commit=$(git rev-parse HEAD~3)
+   '
+
+test_expect_success 'corrupt second commit object' \
+   '
+   perl -i.bak -pe "s/second commit/socond commit/" .git/objects/pack/*.pack &&
+   test_must_fail git fsck --full
+   '
+
+test_expect_success 'rev-list should fail' \
+   '
+   test_must_fail git rev-list --all > /dev/null
+   '
+
+test_expect_success 'git repack _MUST_ fail' \
+   '
+   test_must_fail git repack -a -f -d
+   '
+
+test_expect_success 'first commit is still available' \
+   '
+   git log $first_commit
+   '
+
+test_done
+