Detect the null object ID for symlinks in dir-diff so that difftool can
prepare temporary files that matches how git handles symlinks.
Previously, a null object ID would crash difftool. We now detect null
object IDs and write the symlink's content into the temporary symlink
stand-in file.
Original-patch-by: Johannes Schindelin <johannes.schindelin@xxxxxx>
Signed-off-by: David Aguilar <davvid@xxxxxxxxx>
---
builtin/difftool.c | 36 +++++++++++++++++++++++++++++++++---
t/t7800-difftool.sh | 40 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 73 insertions(+), 3 deletions(-)
diff --git a/builtin/difftool.c b/builtin/difftool.c
index d13350ce83..6c20e20b45 100644
--- a/builtin/difftool.c
+++ b/builtin/difftool.c
@@ -254,6 +254,31 @@ static int ensure_leading_directories(char *path)
}
}
+static int create_symlink_file(struct cache_entry* ce, struct checkout* state)
+{
+ /*
+ * Dereference a worktree symlink and writes its contents
+ * into the checkout state's path.
+ */
+ struct strbuf path = STRBUF_INIT;
+ struct strbuf link = STRBUF_INIT;
+
+ int ok = 0;
+
+ if (strbuf_readlink(&link, ce->name, ce_namelen(ce)) == 0) {
+ strbuf_add(&path, state->base_dir, state->base_dir_len);
+ strbuf_add(&path, ce->name, ce_namelen(ce));
+
+ write_file_buf(path.buf, link.buf, link.len);
+ ok = 1;
+ }
+
+ strbuf_release(&path);
+ strbuf_release(&link);
+
+ return ok;
+}
+
static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
int argc, const char **argv)
{
@@ -376,13 +401,13 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
continue;
}
- if (S_ISLNK(lmode)) {
+ if (S_ISLNK(lmode) && !is_null_oid(&loid)) {
char *content = read_sha1_file(loid.hash, &type, &size);
add_left_or_right(&symlinks2, src_path, content, 0);
free(content);
}
- if (S_ISLNK(rmode)) {
+ if (S_ISLNK(rmode) && !is_null_oid(&roid)) {
char *content = read_sha1_file(roid.hash, &type, &size);
add_left_or_right(&symlinks2, dst_path, content, 1);
free(content);
@@ -414,7 +439,12 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
oidcpy(&ce->oid, &roid);
strcpy(ce->name, dst_path);
ce->ce_namelen = dst_path_len;
- if (checkout_entry(ce, &rstate, NULL))
+
+ if (S_ISLNK(rmode) && is_null_oid(&roid)) {
+ if (!create_symlink_file(ce, &rstate))
+ return error("unable to create symlink file %s",
+ dst_path);
+ } else if (checkout_entry(ce, &rstate, NULL))
return error("could not write '%s'",
dst_path);
} else if (!is_null_oid(&roid)) {
diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
index e1ec292718..64f8e451b5 100755
--- a/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@ -623,4 +623,44 @@ test_expect_success SYMLINKS 'difftool --dir-diff symlinked directories' '
)
'
+test_expect_success SYMLINKS 'difftool --dir-diff' '
+ touch b &&
+ ln -s b c &&
+ git add . &&
+ test_tick &&
+ git commit -m initial &&
+ touch d &&
+ rm c &&
+ ln -s d c &&
+
+ git difftool --dir-diff --extcmd ls >output &&
+ grep -v ^/ output >actual &&
+ cat >expect <<-EOF &&
+ b
+ c
+ dirlinks
+ output
+ submod
+
+ c
+ dirlinks
+ output
+ submod
+ EOF
+ test_cmp expect actual &&
+
+ # The left side contains symlink "c" that points to "b"
+ test_config difftool.cat.cmd "cat \$LOCAL/c" &&
+ git difftool --dir-diff --tool cat >actual &&
+ echo b >expect &&
+ test_cmp expect actual &&
+
+ # The right side contains symlink "c" that points to "d",
+ # which mimics the state of the worktree.
+ test_config difftool.cat.cmd "cat \$REMOTE/c" &&
+ git difftool --dir-diff --tool cat >actual &&
+ echo -n d >expect &&
+ test_cmp expect actual
+'
+
test_done
--
2.12.0.266.g44c9eec009