Merge branch 'cb/leading-path-removal'

* cb/leading-path-removal:
  use persistent memory for rejected paths
  do not overwrite files in leading path
  lstat_cache: optionally return match_len
  add function check_ok_to_remove()
  t7607: add leading-path tests
  t7607: use test-lib functions and check MERGE_HEAD

Conflicts:
	t/t7607-merge-overwrite.sh

cache.h

@@ -859,7 +859,7 @@ struct cache_def {
 
 extern int has_symlink_leading_path(const char *name, int len);
 extern int threaded_has_symlink_leading_path(struct cache_def *, const char *, int);
-extern int has_symlink_or_noent_leading_path(const char *name, int len);
+extern int check_leading_path(const char *name, int len);
 extern int has_dirs_only_path(const char *name, int len, int prefix_len);
 extern void schedule_dir_for_removal(const char *name, int len);
 extern void remove_scheduled_dirs(void);

symlinks.c

@@ -64,11 +64,13 @@ static inline void reset_lstat_cache(struct cache_def *cache)
  * of the prefix, where the cache should use the stat() function
  * instead of the lstat() function to test each path component.
  */
-static int lstat_cache(struct cache_def *cache, const char *name, int len,
-		       int track_flags, int prefix_len_stat_func)
+static int lstat_cache_matchlen(struct cache_def *cache,
+				const char *name, int len,
+				int *ret_flags, int track_flags,
+				int prefix_len_stat_func)
 {
 	int match_len, last_slash, last_slash_dir, previous_slash;
-	int match_flags, ret_flags, save_flags, max_len, ret;
+	int save_flags, max_len, ret;
 	struct stat st;
 
 	if (cache->track_flags != track_flags ||
@@ -90,13 +92,13 @@ static int lstat_cache(struct cache_def *cache, const char *name, int len,
 		match_len = last_slash =
 			longest_path_match(name, len, cache->path, cache->len,
 					   &previous_slash);
-		match_flags = cache->flags & track_flags & (FL_NOENT|FL_SYMLINK);
+		*ret_flags = cache->flags & track_flags & (FL_NOENT|FL_SYMLINK);
 
 		if (!(track_flags & FL_FULLPATH) && match_len == len)
 			match_len = last_slash = previous_slash;
 
-		if (match_flags && match_len == cache->len)
-			return match_flags;
+		if (*ret_flags && match_len == cache->len)
+			return match_len;
 		/*
 		 * If we now have match_len > 0, we would know that
 		 * the matched part will always be a directory.
@@ -105,16 +107,16 @@ static int lstat_cache(struct cache_def *cache, const char *name, int len,
 		 * a substring of the cache on a path component basis,
 		 * we can return immediately.
 		 */
-		match_flags = track_flags & FL_DIR;
-		if (match_flags && len == match_len)
-			return match_flags;
+		*ret_flags = track_flags & FL_DIR;
+		if (*ret_flags && len == match_len)
+			return match_len;
 	}
 
 	/*
 	 * Okay, no match from the cache so far, so now we have to
 	 * check the rest of the path components.
 	 */
-	ret_flags = FL_DIR;
+	*ret_flags = FL_DIR;
 	last_slash_dir = last_slash;
 	max_len = len < PATH_MAX ? len : PATH_MAX;
 	while (match_len < max_len) {
@@ -133,16 +135,16 @@ static int lstat_cache(struct cache_def *cache, const char *name, int len,
 			ret = lstat(cache->path, &st);
 
 		if (ret) {
-			ret_flags = FL_LSTATERR;
+			*ret_flags = FL_LSTATERR;
 			if (errno == ENOENT)
-				ret_flags |= FL_NOENT;
+				*ret_flags |= FL_NOENT;
 		} else if (S_ISDIR(st.st_mode)) {
 			last_slash_dir = last_slash;
 			continue;
 		} else if (S_ISLNK(st.st_mode)) {
-			ret_flags = FL_SYMLINK;
+			*ret_flags = FL_SYMLINK;
 		} else {
-			ret_flags = FL_ERR;
+			*ret_flags = FL_ERR;
 		}
 		break;
 	}
@@ -152,7 +154,7 @@ static int lstat_cache(struct cache_def *cache, const char *name, int len,
 	 * path types, FL_NOENT, FL_SYMLINK and FL_DIR, can be cached
 	 * for the moment!
 	 */
-	save_flags = ret_flags & track_flags & (FL_NOENT|FL_SYMLINK);
+	save_flags = *ret_flags & track_flags & (FL_NOENT|FL_SYMLINK);
 	if (save_flags && last_slash > 0 && last_slash <= PATH_MAX) {
 		cache->path[last_slash] = '\0';
 		cache->len = last_slash;
@@ -176,7 +178,16 @@ static int lstat_cache(struct cache_def *cache, const char *name, int len,
 	} else {
 		reset_lstat_cache(cache);
 	}
-	return ret_flags;
+	return match_len;
+}
+
+static int lstat_cache(struct cache_def *cache, const char *name, int len,
+		       int track_flags, int prefix_len_stat_func)
+{
+	int flags;
+	(void)lstat_cache_matchlen(cache, name, len, &flags, track_flags,
+			prefix_len_stat_func);
+	return flags;
 }
 
 #define USE_ONLY_LSTAT  0
@@ -198,15 +209,26 @@ int has_symlink_leading_path(const char *name, int len)
 }
 
 /*
- * Return non-zero if path 'name' has a leading symlink component or
+ * Return zero if path 'name' has a leading symlink component or
  * if some leading path component does not exists.
+ *
+ * Return -1 if leading path exists and is a directory.
+ *
+ * Return path length if leading path exists and is neither a
+ * directory nor a symlink.
  */
-int has_symlink_or_noent_leading_path(const char *name, int len)
+int check_leading_path(const char *name, int len)
 {
 	struct cache_def *cache = &default_cache;	/* FIXME */
-	return lstat_cache(cache, name, len,
-			   FL_SYMLINK|FL_NOENT|FL_DIR, USE_ONLY_LSTAT) &
-		(FL_SYMLINK|FL_NOENT);
+	int flags;
+	int match_len = lstat_cache_matchlen(cache, name, len, &flags,
+			   FL_SYMLINK|FL_NOENT|FL_DIR, USE_ONLY_LSTAT);
+	if (flags & (FL_SYMLINK|FL_NOENT))
+		return 0;
+	else if (flags & FL_DIR)
+		return -1;
+	else
+		return match_len;
 }
 
 /*

t/t7607-merge-overwrite.sh

@@ -7,48 +7,54 @@ Do not overwrite changes.'
 . ./test-lib.sh
 
 test_expect_success 'setup' '
-	echo c0 > c0.c &&
-	git add c0.c &&
-	git commit -m c0 &&
-	git tag c0 &&
-	echo c1 > c1.c &&
-	git add c1.c &&
-	git commit -m c1 &&
-	git tag c1 &&
+	test_commit c0 c0.c &&
+	test_commit c1 c1.c &&
+	test_commit c1a c1.c "c1 a" &&
 	git reset --hard c0 &&
-	echo c2 > c2.c &&
-	git add c2.c &&
-	git commit -m c2 &&
-	git tag c2 &&
-	git reset --hard c1 &&
-	echo "c1 a" > c1.c &&
-	git add c1.c &&
-	git commit -m "c1 a" &&
-	git tag c1a &&
+	test_commit c2 c2.c &&
+	git reset --hard c0 &&
+	mkdir sub &&
+	echo "sub/f" > sub/f &&
+	mkdir sub2 &&
+	echo "sub2/f" > sub2/f &&
+	git add sub/f sub2/f &&
+	git commit -m sub &&
+	git tag sub &&
 	echo "VERY IMPORTANT CHANGES" > important
 '
 
 test_expect_success 'will not overwrite untracked file' '
 	git reset --hard c1 &&
-	cat important > c2.c &&
+	cp important c2.c &&
 	test_must_fail git merge c2 &&
+	test_path_is_missing .git/MERGE_HEAD &&
 	test_cmp important c2.c
 '
 
+test_expect_success 'will overwrite tracked file' '
+	git reset --hard c1 &&
+	cp important c2.c &&
+	git add c2.c &&
+	git commit -m important &&
+	git checkout c2
+'
+
 test_expect_success 'will not overwrite new file' '
 	git reset --hard c1 &&
-	cat important > c2.c &&
+	cp important c2.c &&
 	git add c2.c &&
 	test_must_fail git merge c2 &&
+	test_path_is_missing .git/MERGE_HEAD &&
 	test_cmp important c2.c
 '
 
 test_expect_success 'will not overwrite staged changes' '
 	git reset --hard c1 &&
-	cat important > c2.c &&
+	cp important c2.c &&
 	git add c2.c &&
 	rm c2.c &&
 	test_must_fail git merge c2 &&
+	test_path_is_missing .git/MERGE_HEAD &&
 	git checkout c2.c &&
 	test_cmp important c2.c
 '
@@ -57,7 +63,7 @@ test_expect_success 'will not overwrite removed file' '
 	git reset --hard c1 &&
 	git rm c1.c &&
 	git commit -m "rm c1.c" &&
-	cat important > c1.c &&
+	cp important c1.c &&
 	test_must_fail git merge c1a &&
 	test_cmp important c1.c
 '
@@ -66,24 +72,74 @@ test_expect_success 'will not overwrite re-added file' '
 	git reset --hard c1 &&
 	git rm c1.c &&
 	git commit -m "rm c1.c" &&
-	cat important > c1.c &&
+	cp important c1.c &&
 	git add c1.c &&
 	test_must_fail git merge c1a &&
+	test_path_is_missing .git/MERGE_HEAD &&
 	test_cmp important c1.c
 '
 
 test_expect_success 'will not overwrite removed file with staged changes' '
 	git reset --hard c1 &&
 	git rm c1.c &&
 	git commit -m "rm c1.c" &&
-	cat important > c1.c &&
+	cp important c1.c &&
 	git add c1.c &&
 	rm c1.c &&
 	test_must_fail git merge c1a &&
+	test_path_is_missing .git/MERGE_HEAD &&
 	git checkout c1.c &&
 	test_cmp important c1.c
 '
 
+test_expect_success 'will not overwrite untracked subtree' '
+	git reset --hard c0 &&
+	rm -rf sub &&
+	mkdir -p sub/f &&
+	cp important sub/f/important &&
+	test_must_fail git merge sub &&
+	test_path_is_missing .git/MERGE_HEAD &&
+	test_cmp important sub/f/important
+'
+
+cat >expect <<\EOF
+error: The following untracked working tree files would be overwritten by merge:
+	sub
+	sub2
+Please move or remove them before you can merge.
+EOF
+
+test_expect_success 'will not overwrite untracked file in leading path' '
+	git reset --hard c0 &&
+	rm -rf sub &&
+	cp important sub &&
+	cp important sub2 &&
+	test_must_fail git merge sub 2>out &&
+	test_cmp out expect &&
+	test_path_is_missing .git/MERGE_HEAD &&
+	test_cmp important sub &&
+	test_cmp important sub2 &&
+	rm -f sub sub2
+'
+
+test_expect_failure SYMLINKS 'will not overwrite untracked symlink in leading path' '
+	git reset --hard c0 &&
+	rm -rf sub &&
+	mkdir sub2 &&
+	ln -s sub2 sub &&
+	test_must_fail git merge sub &&
+	test_path_is_missing .git/MERGE_HEAD
+'
+
+test_expect_success SYMLINKS 'will not be confused by symlink in leading path' '
+	git reset --hard c0 &&
+	rm -rf sub &&
+	ln -s sub2 sub &&
+	git add sub &&
+	git commit -m ln &&
+	git checkout sub
+'
+
 cat >expect <<\EOF
 error: Untracked working tree file 'c0.c' would be overwritten by merge.
 fatal: read-tree failed

t/t7609-merge-co-error-msgs.sh

@@ -27,10 +27,10 @@ test_expect_success 'setup' '
 
 cat >expect <<\EOF
 error: The following untracked working tree files would be overwritten by merge:
-	two
-	three
-	four
 	five
+	four
+	three
+	two
 Please move or remove them before you can merge.
 EOF
 
@@ -49,9 +49,9 @@ test_expect_success 'untracked files overwritten by merge (fast and non-fast for
 
 cat >expect <<\EOF
 error: Your local changes to the following files would be overwritten by merge:
-	two
-	three
 	four
+	three
+	two
 Please, commit your changes or stash them before you can merge.
 error: The following untracked working tree files would be overwritten by merge:
 	five
@@ -68,8 +68,8 @@ test_expect_success 'untracked files or local changes ovewritten by merge' '
 
 cat >expect <<\EOF
 error: Your local changes to the following files would be overwritten by checkout:
-	rep/two
 	rep/one
+	rep/two
 Please, commit your changes or stash them before you can switch branches.
 EOF
 
@@ -89,8 +89,8 @@ test_expect_success 'cannot switch branches because of local changes' '
 
 cat >expect <<\EOF
 error: Your local changes to the following files would be overwritten by checkout:
-	rep/two
 	rep/one
+	rep/two
 Please, commit your changes or stash them before you can switch branches.
 EOF
 
@@ -102,8 +102,8 @@ test_expect_success 'not uptodate file porcelain checkout error' '
 
 cat >expect <<\EOF
 error: Updating the following directories would lose untracked files in it:
-	rep2
 	rep
+	rep2
 
 EOF