worktree: don't segfault with an absolute pathspec without a work tree

If a command is run with an absolute path as a pathspec inside a bare
repository, e.g. "rev-list HEAD -- /home", the code tried to run strlen()
on NULL, which is the result of get_git_work_tree(), and segfaulted.  It
should just fail instead.

Currently the function returns NULL even inside .git/ in a repository
with a work tree, but that is a separate issue.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/setup.c b/setup.c
index 029371e5844a1069d62456c6bb51028efbb671c4..4272ec0ef2fd833923a5303286a0dd237ec6eab8 100644 (file)
--- a/setup.c
+++ b/setup.c
@@ -18,9 +18,12 @@ const char *prefix_path(const char *prefix, int len, const char *path)
        if (normalize_path_copy(sanitized, sanitized))
                goto error_out;
        if (is_absolute_path(orig)) {
+               size_t len, total;
                const char *work_tree = get_git_work_tree();
-               size_t len = strlen(work_tree);
-               size_t total = strlen(sanitized) + 1;
+               if (!work_tree)
+                       goto error_out;
+               len = strlen(work_tree);
+               total = strlen(sanitized) + 1;
                if (strncmp(sanitized, work_tree, len) ||
                    (sanitized[len] != '\0' && sanitized[len] != '/')) {
                error_out:

diff --git a/t/t1501-worktree.sh b/t/t1501-worktree.sh
index f6a6f839a18de4c3775ea965f164d0d20f2bbe9b..74e6443664010196f2694304179917fdadc53c01 100755 (executable)
--- a/t/t1501-worktree.sh
+++ b/t/t1501-worktree.sh
@@ -174,4 +174,19 @@ test_expect_success 'git grep' '
        GIT_DIR=../.. GIT_WORK_TREE=.. git grep -l changed | grep dir/tracked)
 '
 
+test_expect_success 'git commit' '
+       (
+               cd repo.git &&
+               GIT_DIR=. GIT_WORK_TREE=work git commit -a -m done
+       )
+'
+
+test_expect_success 'absolute pathspec should fail gracefully' '
+       (
+               cd repo.git || exit 1
+               git config --unset core.worktree
+               test_must_fail git log HEAD -- /home
+       )
+'
+
 test_done