Enable inverted patterns in NoExtract and NoUpgrade.

It is now possible to invert patterns in NoExtract and NoUpgrade.
This feature allows users to whitelist certain files that were
previously blacklisted by another entry.

Signed-off-by: Allan McRae <allan@archlinux.org>

1 files changed, 31 insertions, 0 deletions

diff --git a/lib/libalpm/util.c b/lib/libalpm/util.c
index f84fb666..15c1a67c 100644
--- a/lib/libalpm/util.c
+++ b/lib/libalpm/util.c
@@ -1249,6 +1249,37 @@ int _alpm_access(alpm_handle_t *handle, const char *dir, const char *file, int a
 	return ret;
 }
 
+/** Checks whether a string matches at least one shell wildcard pattern.
+ * Checks for matches with fnmatch. Matches are inverted by prepending
+ * patterns with an exclamation mark. Preceding exclamation marks may be
+ * escaped. Subsequent matches override previous ones.
+ * @param patterns patterns to match against
+ * @param string string to check against pattern
+ * @return 0 if string matches pattern, negative if they don't match and
+ * positive if the last match was inverted
+ */
+int _alpm_fnmatch_patterns(alpm_list_t *patterns, const char *string)
+{
+	alpm_list_t *i;
+	char *pattern;
+	short inverted;
+
+	for(i = alpm_list_last(patterns); i; i = alpm_list_previous(i)) {
+		pattern = i->data;
+
+		inverted = pattern[0] == '!';
+		if(inverted || pattern[0] == '\\') {
+			pattern++;
+		}
+
+		if(_alpm_fnmatch(pattern, string) == 0) {
+			return inverted;
+		}
+	}
+
+	return -1;
+}
+
 /** Checks whether a string matches a shell wildcard pattern.
  * Wrapper around fnmatch.
  * @param pattern pattern to match against