match_pathspec() -- return how well the spec matched

This updates the return value from match_pathspec() so that the
caller can tell cases between exact match, leading pathname
match (i.e. file "foo/bar" matches a pathspec "foo"), or
filename glob match.  This can be used to prevent "rm dir" from
removing "dir/file" without explicitly asking for recursive
behaviour with -r flag, for example.

Signed-off-by: Junio C Hamano <junkio@cox.net>

dir.c

@@ -40,6 +40,18 @@ int common_prefix(const char **pathspec)
 	return prefix;
 }
 
+/*
+ * Does 'match' matches the given name?
+ * A match is found if
+ *
+ * (1) the 'match' string is leading directory of 'name', or
+ * (2) the 'match' string is a wildcard and matches 'name', or
+ * (3) the 'match' string is exactly the same as 'name'.
+ *
+ * and the return value tells which case it was.
+ *
+ * It returns 0 when there is no match.
+ */
 static int match_one(const char *match, const char *name, int namelen)
 {
 	int matchlen;
@@ -47,27 +59,30 @@ static int match_one(const char *match, const char *name, int namelen)
 	/* If the match was just the prefix, we matched */
 	matchlen = strlen(match);
 	if (!matchlen)
-		return 1;
+		return MATCHED_RECURSIVELY;
 
 	/*
 	 * If we don't match the matchstring exactly,
 	 * we need to match by fnmatch
 	 */
 	if (strncmp(match, name, matchlen))
-		return !fnmatch(match, name, 0);
+		return !fnmatch(match, name, 0) ? MATCHED_FNMATCH : 0;
 
-	/*
-	 * If we did match the string exactly, we still
-	 * need to make sure that it happened on a path
-	 * component boundary (ie either the last character
-	 * of the match was '/', or the next character of
-	 * the name was '/' or the terminating NUL.
-	 */
-	return	match[matchlen-1] == '/' ||
-		name[matchlen] == '/' ||
-		!name[matchlen];
+	if (!name[matchlen])
+		return MATCHED_EXACTLY;
+	if (match[matchlen-1] == '/' || name[matchlen] == '/')
+		return MATCHED_RECURSIVELY;
+	return 0;
 }
 
+/*
+ * Given a name and a list of pathspecs, see if the name matches
+ * any of the pathspecs.  The caller is also interested in seeing
+ * all pathspec matches some names it calls this function with
+ * (otherwise the user could have mistyped the unmatched pathspec),
+ * and a mark is left in seen[] array for pathspec element that
+ * actually matched anything.
+ */
 int match_pathspec(const char **pathspec, const char *name, int namelen, int prefix, char *seen)
 {
 	int retval;
@@ -77,12 +92,16 @@ int match_pathspec(const char **pathspec, const char *name, int namelen, int pre
 	namelen -= prefix;
 
 	for (retval = 0; (match = *pathspec++) != NULL; seen++) {
-		if (retval & *seen)
+		int how;
+		if (retval && *seen == MATCHED_EXACTLY)
 			continue;
 		match += prefix;
-		if (match_one(match, name, namelen)) {
-			retval = 1;
-			*seen = 1;
+		how = match_one(match, name, namelen);
+		if (how) {
+			if (retval < how)
+				retval = how;
+			if (*seen < how)
+				*seen = how;
 		}
 	}
 	return retval;

dir.h

@@ -40,6 +40,10 @@ struct dir_struct {
 };
 
 extern int common_prefix(const char **pathspec);
+
+#define MATCHED_RECURSIVELY 1
+#define MATCHED_FNMATCH 2
+#define MATCHED_EXACTLY 3
 extern int match_pathspec(const char **pathspec, const char *name, int namelen, int prefix, char *seen);
 
 extern int read_directory(struct dir_struct *, const char *path, const char *base, int baselen);