gitignore(5): Allow "foo/" in ignore list to match directory "foo"

A pattern "foo/" in the exclude list did not match directory
"foo", but a pattern "foo" did.  This attempts to extend the
exclude mechanism so that it would while not matching a regular
file or a symbolic link "foo".  In order to differentiate a
directory and non directory, this passes down the type of path
being checked to excluded() function.

A downside is that the recursive directory walk may need to run
lstat(2) more often on systems whose "struct dirent" do not give
the type of the entry; earlier it did not have to do so for an
excluded path, but we now need to figure out if a path is a
directory before deciding to exclude it.  This is especially bad
because an idea similar to the earlier CE_UPTODATE optimization
to reduce number of lstat(2) calls would by definition not apply
to the codepaths involved, as (1) directories will not be
registered in the index, and (2) excluded paths will not be in
the index anyway.

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

1 files changed, 31 insertions, 11 deletions

diff --git a/dir.c b/dir.c
index 3e345c2fc..a4f8c258c 100644
--- a/dir.c
+++ b/dir.c
@@ -126,18 +126,34 @@ static int no_wildcard(const char *string)
 void add_exclude(const char *string, const char *base,
 		 int baselen, struct exclude_list *which)
 {
-	struct exclude *x = xmalloc(sizeof (*x));
+	struct exclude *x;
+	size_t len;
+	int to_exclude = 1;
+	int flags = 0;
 
-	x->to_exclude = 1;
 	if (*string == '!') {
-		x->to_exclude = 0;
+		to_exclude = 0;
 		string++;
 	}
-	x->pattern = string;
+	len = strlen(string);
+	if (len && string[len - 1] == '/') {
+		char *s;
+		x = xmalloc(sizeof(*x) + len);
+		s = (char*)(x+1);
+		memcpy(s, string, len - 1);
+		s[len - 1] = '\0';
+		string = s;
+		x->pattern = s;
+		flags = EXC_FLAG_MUSTBEDIR;
+	} else {
+		x = xmalloc(sizeof(*x));
+		x->pattern = string;
+	}
+	x->to_exclude = to_exclude;
 	x->patternlen = strlen(string);
 	x->base = base;
 	x->baselen = baselen;
-	x->flags = 0;
+	x->flags = flags;
 	if (!strchr(string, '/'))
 		x->flags |= EXC_FLAG_NODIR;
 	if (no_wildcard(string))
@@ -261,7 +277,7 @@ static void prep_exclude(struct dir_struct *dir, const char *base, int baselen)
  * Return 1 for exclude, 0 for include and -1 for undecided.
  */
 static int excluded_1(const char *pathname,
-		      int pathlen, const char *basename,
+		      int pathlen, const char *basename, int dtype,
 		      struct exclude_list *el)
 {
 	int i;
@@ -272,6 +288,10 @@ static int excluded_1(const char *pathname,
 			const char *exclude = x->pattern;
 			int to_exclude = x->to_exclude;
 
+			if ((x->flags & EXC_FLAG_MUSTBEDIR) &&
+			    (dtype != DT_DIR))
+				continue;
+
 			if (x->flags & EXC_FLAG_NODIR) {
 				/* match basename */
 				if (x->flags & EXC_FLAG_NOWILDCARD) {
@@ -314,7 +334,7 @@ static int excluded_1(const char *pathname,
 	return -1; /* undecided */
 }
 
-int excluded(struct dir_struct *dir, const char *pathname)
+int excluded(struct dir_struct *dir, const char *pathname, int dtype)
 {
 	int pathlen = strlen(pathname);
 	int st;
@@ -323,7 +343,8 @@ int excluded(struct dir_struct *dir, const char *pathname)
 
 	prep_exclude(dir, pathname, basename-pathname);
 	for (st = EXC_CMDL; st <= EXC_FILE; st++) {
-		switch (excluded_1(pathname, pathlen, basename, &dir->exclude_list[st])) {
+		switch (excluded_1(pathname, pathlen, basename,
+				   dtype, &dir->exclude_list[st])) {
 		case 0:
 			return 0;
 		case 1:
@@ -560,7 +581,8 @@ static int read_directory_recursive(struct dir_struct *dir, const char *path, co
 			if (simplify_away(fullname, baselen + len, simplify))
 				continue;
 
-			exclude = excluded(dir, fullname);
+			dtype = get_dtype(de, fullname);
+			exclude = excluded(dir, fullname, dtype);
 			if (exclude && dir->collect_ignored
 			    && in_pathspec(fullname, baselen + len, simplify))
 				dir_add_ignored(dir, fullname, baselen + len);
@@ -572,8 +594,6 @@ static int read_directory_recursive(struct dir_struct *dir, const char *path, co
 			if (exclude && !dir->show_ignored)
 				continue;
 
-			dtype = get_dtype(de, fullname);
-
 			/*
 			 * Do we want to see just the ignored files?
 			 * We still need to recurse into directories,