pacman+libalpm: handle search errors

Previously, pacman treated no matches and an error during search the
same.

To fix this, alpm_db_search now returns its status as an int and
instead takes the to be returned list as a param. Allowing front ends to
easily differentiate between errors and no matches.

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

lib/libalpm/alpm.h

@@ -997,9 +997,11 @@ alpm_list_t *alpm_db_get_groupcache(alpm_db_t *db);
 /** Searches a database with regular expressions.
  * @param db pointer to the package database to search in
  * @param needles a list of regular expressions to search for
- * @return the list of packages matching all regular expressions on success, NULL on error
+ * @param ret the list of packages matching all regular expressions
+ * @return 0 on success, -1 on error (pm_errno is set accordingly)
  */
-alpm_list_t *alpm_db_search(alpm_db_t *db, const alpm_list_t *needles);
+int alpm_db_search(alpm_db_t *db, const alpm_list_t *needles,
+		alpm_list_t **ret);
 
 typedef enum _alpm_db_usage_t {
 	ALPM_DB_USAGE_SYNC = 1,

lib/libalpm/db.c

@@ -298,12 +298,14 @@ alpm_list_t SYMEXPORT *alpm_db_get_groupcache(alpm_db_t *db)
 }
 
 /** Searches a database. */
-alpm_list_t SYMEXPORT *alpm_db_search(alpm_db_t *db, const alpm_list_t *needles)
+int SYMEXPORT alpm_db_search(alpm_db_t *db, const alpm_list_t *needles,
+		alpm_list_t **ret)
 {
-	ASSERT(db != NULL, return NULL);
+	ASSERT(db != NULL && ret != NULL && *ret == NULL,
+			RET_ERR(db->handle, ALPM_ERR_WRONG_ARGS, -1));
 	db->handle->pm_errno = ALPM_ERR_OK;
 
-	return _alpm_db_search(db, needles);
+	return _alpm_db_search(db, needles, ret);
 }
 
 /** Sets the usage bitmask for a repo */
@@ -396,13 +398,13 @@ int _alpm_db_cmp(const void *d1, const void *d2)
 	return strcmp(db1->treename, db2->treename);
 }
 
-alpm_list_t *_alpm_db_search(alpm_db_t *db, const alpm_list_t *needles)
+int _alpm_db_search(alpm_db_t *db, const alpm_list_t *needles,
+		alpm_list_t **ret)
 {
 	const alpm_list_t *i, *j, *k;
-	alpm_list_t *ret = NULL;
 
 	if(!(db->usage & ALPM_DB_USAGE_SEARCH)) {
-		return NULL;
+		return 0;
 	}
 
 	/* copy the pkgcache- we will free the list var after each needle */
@@ -415,12 +417,12 @@ alpm_list_t *_alpm_db_search(alpm_db_t *db, const alpm_list_t *needles)
 		if(i->data == NULL) {
 			continue;
 		}
-		ret = NULL;
+		*ret = NULL;
 		targ = i->data;
 		_alpm_log(db->handle, ALPM_LOG_DEBUG, "searching for target '%s'\n", targ);
 
 		if(regcomp(&reg, targ, REG_EXTENDED | REG_NOSUB | REG_ICASE | REG_NEWLINE) != 0) {
-			RET_ERR(db->handle, ALPM_ERR_INVALID_REGEX, NULL);
+			RET_ERR(db->handle, ALPM_ERR_INVALID_REGEX, -1);
 		}
 
 		for(j = list; j; j = j->next) {
@@ -463,18 +465,18 @@ alpm_list_t *_alpm_db_search(alpm_db_t *db, const alpm_list_t *needles)
 				_alpm_log(db->handle, ALPM_LOG_DEBUG,
 						"search target '%s' matched '%s' on package '%s'\n",
 						targ, matched, name);
-				ret = alpm_list_add(ret, pkg);
+				*ret = alpm_list_add(*ret, pkg);
 			}
 		}
 
 		/* Free the existing search list, and use the returned list for the
 		 * next needle. This allows for AND-based package searching. */
 		alpm_list_free(list);
-		list = ret;
+		list = *ret;
 		regfree(&reg);
 	}
 
-	return ret;
+	return 0;
 }
 
 /* Returns a new package cache from db.

lib/libalpm/db.h

@@ -87,7 +87,8 @@ alpm_db_t *_alpm_db_new(const char *treename, int is_local);
 void _alpm_db_free(alpm_db_t *db);
 const char *_alpm_db_path(alpm_db_t *db);
 int _alpm_db_cmp(const void *d1, const void *d2);
-alpm_list_t *_alpm_db_search(alpm_db_t *db, const alpm_list_t *needles);
+int _alpm_db_search(alpm_db_t *db, const alpm_list_t *needles,
+		alpm_list_t **ret);
 alpm_db_t *_alpm_db_register_local(alpm_handle_t *handle);
 alpm_db_t *_alpm_db_register_sync(alpm_handle_t *handle, const char *treename,
 		int level);

src/pacman/package.c

@@ -518,12 +518,13 @@ void print_groups(alpm_pkg_t *pkg)
  * @param db the database we're searching
  * @param targets the targets we're searching for
  * @param show_status show if the package is also in the local db
+ * @return -1 on error, 0 if there were matches, 1 if there were not
  */
 int dump_pkg_search(alpm_db_t *db, alpm_list_t *targets, int show_status)
 {
 	int freelist = 0;
 	alpm_db_t *db_local;
-	alpm_list_t *i, *searchlist;
+	alpm_list_t *i, *searchlist = NULL;
 	unsigned short cols;
 	const colstr_t *colstr = &config->colstr;
 
@@ -533,7 +534,9 @@ int dump_pkg_search(alpm_db_t *db, alpm_list_t *targets, int show_status)
 
 	/* if we have a targets list, search for packages matching it */
 	if(targets) {
-		searchlist = alpm_db_search(db, targets);
+		if(alpm_db_search(db, targets, &searchlist) != 0) {
+			return -1;
+		}
 		freelist = 1;
 	} else {
 		searchlist = alpm_db_get_pkgcache(db);

src/pacman/query.c

@@ -233,7 +233,15 @@ targcleanup:
 static int query_search(alpm_list_t *targets)
 {
 	alpm_db_t *db_local = alpm_get_localdb(config->handle);
-	return dump_pkg_search(db_local, targets, 0);
+	int ret = dump_pkg_search(db_local, targets, 0);
+	if(ret == -1) {
+		alpm_errno_t err = alpm_errno(config->handle);
+		pm_printf(ALPM_LOG_ERROR, "search failed: %s\n", alpm_strerror(err));
+		return 1;
+	}
+
+	return ret;
+
 }
 
 static unsigned short pkg_get_locality(alpm_pkg_t *pkg)

src/pacman/sync.c

@@ -311,7 +311,15 @@ static int sync_search(alpm_list_t *syncs, alpm_list_t *targets)
 
 	for(i = syncs; i; i = alpm_list_next(i)) {
 		alpm_db_t *db = i->data;
-		found += !dump_pkg_search(db, targets, 1);
+		int ret = dump_pkg_search(db, targets, 1);
+
+		if(ret == -1) {
+			alpm_errno_t err = alpm_errno(config->handle);
+			pm_printf(ALPM_LOG_ERROR, "search failed: %s\n", alpm_strerror(err));
+			return 1;
+		}
+
+		found += !ret;
 	}
 
 	return (found == 0);