pathspec: do exact comparison on the leading non-wildcard part

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

dir.c

@@ -34,6 +34,21 @@ int fnmatch_icase(const char *pattern, const char *string, int flags)
 	return fnmatch(pattern, string, flags | (ignore_case ? FNM_CASEFOLD : 0));
 }
 
+inline int git_fnmatch(const char *pattern, const char *string,
+		       int flags, int prefix)
+{
+	int fnm_flags = 0;
+	if (flags & GFNM_PATHNAME)
+		fnm_flags |= FNM_PATHNAME;
+	if (prefix > 0) {
+		if (strncmp(pattern, string, prefix))
+			return FNM_NOMATCH;
+		pattern += prefix;
+		string += prefix;
+	}
+	return fnmatch(pattern, string, fnm_flags);
+}
+
 static size_t common_prefix_len(const char **pathspec)
 {
 	const char *n, *first;
@@ -230,7 +245,8 @@ static int match_pathspec_item(const struct pathspec_item *item, int prefix,
 			return MATCHED_RECURSIVELY;
 	}
 
-	if (item->nowildcard_len < item->len && !fnmatch(match, name, 0))
+	if (item->nowildcard_len < item->len &&
+	    !git_fnmatch(match, name, 0, item->nowildcard_len - prefix))
 		return MATCHED_FNMATCH;
 
 	return 0;

dir.h

@@ -139,4 +139,12 @@ extern int strcmp_icase(const char *a, const char *b);
 extern int strncmp_icase(const char *a, const char *b, size_t count);
 extern int fnmatch_icase(const char *pattern, const char *string, int flags);
 
+/*
+ * The prefix part of pattern must not contains wildcards.
+ */
+#define GFNM_PATHNAME 1		/* similar to FNM_PATHNAME */
+
+extern int git_fnmatch(const char *pattern, const char *string,
+		       int flags, int prefix);
+
 #endif

tree-walk.c

@@ -627,7 +627,8 @@ enum interesting tree_entry_interesting(const struct name_entry *entry,
 				return entry_interesting;
 
 			if (item->nowildcard_len < item->len) {
-				if (!fnmatch(match + baselen, entry->path, 0))
+				if (!git_fnmatch(match + baselen, entry->path,
+						 0, item->nowildcard_len - baselen))
 					return entry_interesting;
 
 				/*
@@ -652,7 +653,8 @@ match_wildcards:
 
 		strbuf_add(base, entry->path, pathlen);
 
-		if (!fnmatch(match, base->buf + base_offset, 0)) {
+		if (!git_fnmatch(match, base->buf + base_offset,
+				 0, item->nowildcard_len)) {
 			strbuf_setlen(base, base_offset + baselen);
 			return entry_interesting;
 		}