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>

3 files changed, 34 insertions, 2 deletions

diff --git a/lib/libalpm/add.c b/lib/libalpm/add.c
index cab04a8b..3d0cf55a 100644
--- a/lib/libalpm/add.c
+++ b/lib/libalpm/add.c
@@ -183,7 +183,7 @@ static int extract_single_file(alpm_handle_t *handle, struct archive *archive,
 	}
 
 	/* if a file is in NoExtract then we never extract it */
-	if(alpm_list_find(handle->noextract, entryname, _alpm_fnmatch)) {
+	if(_alpm_fnmatch_patterns(handle->noextract, entryname) == 0) {
 		_alpm_log(handle, ALPM_LOG_DEBUG, "%s is in NoExtract,"
 				" skipping extraction of %s\n",
 				entryname, filename);
@@ -245,7 +245,7 @@ static int extract_single_file(alpm_handle_t *handle, struct archive *archive,
 		} else {
 			/* case 3: */
 			/* if file is in NoUpgrade, don't touch it */
-			if(alpm_list_find(handle->noupgrade, entryname, _alpm_fnmatch)) {
+			if(_alpm_fnmatch_patterns(handle->noupgrade, entryname) == 0) {
 				notouch = 1;
 			} else {
 				alpm_backup_t *backup;
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
diff --git a/lib/libalpm/util.h b/lib/libalpm/util.h
index 56031f3e..24b7c229 100644
--- a/lib/libalpm/util.h
+++ b/lib/libalpm/util.h
@@ -140,6 +140,7 @@ alpm_time_t _alpm_parsedate(const char *line);
 int _alpm_raw_cmp(const char *first, const char *second);
 int _alpm_raw_ncmp(const char *first, const char *second, size_t max);
 int _alpm_access(alpm_handle_t *handle, const char *dir, const char *file, int amode);
+int _alpm_fnmatch_patterns(alpm_list_t *patterns, const char *string);
 int _alpm_fnmatch(const void *pattern, const void *string);
 
 #ifndef HAVE_STRSEP