Index: res/res_config_sqlite.c
===================================================================
--- res/res_config_sqlite.c	(revision 131914)
+++ res/res_config_sqlite.c	(working copy)
@@ -129,19 +129,26 @@
 
 /*!
  * Maximum number of loops before giving up executing a query. Calls to
- * sqlite_xxx() functions which can return SQLITE_BUSY or SQLITE_LOCKED
- * are enclosed by RES_CONFIG_SQLITE_BEGIN and RES_CONFIG_SQLITE_END, e.g.
+ * sqlite_xxx() functions which can return SQLITE_BUSY are enclosed by
+ * RES_CONFIG_SQLITE_BEGIN and RES_CONFIG_SQLITE_END, e.g.
  * <pre>
- * char *errormsg;
+ * char *errormsg = NULL;
  * int error;
  *
  * RES_CONFIG_SQLITE_BEGIN
  *	 error = sqlite_exec(db, query, NULL, NULL, &errormsg);
- * RES_CONFIG_SQLITE_END(error)
+ * RES_CONFIG_SQLITE_END(error, errormsg)
  *
  * if (error)
  *	 ...;
+ *
+ * sqlite_freemem(errormsg);
+ * errormsg = NULL;
  * </pre>
+ *
+ * Note that RES_CONFIG_SQLITE_END(error, NULL) will NOT work because NULL
+ * is not an lvalue.  If &errormsg is replaced by NULL in the SQLite function
+ * call, a new variant of RES_CONFIG_SQLITE_END will have to be written.
  */
 #define RES_CONFIG_SQLITE_MAX_LOOPS 10
 
@@ -152,23 +159,42 @@
  */
 #define RES_CONFIG_SQLITE_BEGIN						\
 MACRO_BEGIN								\
-	int __i;							\
+	int __i = 0;							\
 									\
-	for (__i = 0; __i < RES_CONFIG_SQLITE_MAX_LOOPS; __i++)	{
+	while (1) {
 
 /*!
  * Macro used after executing a query.
  *
  * \see RES_CONFIG_SQLITE_MAX_LOOPS.
  */
-#define RES_CONFIG_SQLITE_END(error)					\
-		if (error != SQLITE_BUSY && error != SQLITE_LOCKED)	\
+#define RES_CONFIG_SQLITE_END(error, errormsg)				\
+		if (error != SQLITE_BUSY)				\
 			break;						\
 		usleep(1000);						\
+		if (++__i >= RES_CONFIG_SQLITE_MAX_LOOPS)		\
+			break;						\
+		if (errormsg) {						\
+			sqlite_freemem(errormsg);			\
+			errormsg = NULL;				\
+		}							\
 	}								\
 MACRO_END;
 
 /*!
+ * Macro that simply returns errormsg if available (not NULL) or else
+ * returns a static string description of the error code.
+ * This macro is useful when an SQLite error message is to be logged
+ * somewhere, because SQLite can't give us any hard warranty that the
+ * allocation of the errormsg will succeed, and if it fails errormsg
+ * will remain NULL despite error being set.
+ * However, errormsg is sometimes more precise so in the general case
+ * it is what we want to log.
+ */
+#define RES_CONFIG_SQLITE_ERRORMSG(errormsg, error)			\
+	((errormsg) ? (errormsg) : sqlite_error_string(error))
+
+/*!
  * Structure sent to the SQLite callback function for static configuration.
  *
  * \see add_cfg_entry()
@@ -657,7 +683,7 @@
 
 static int cdr_handler(struct ast_cdr *cdr)
 {
-	char *query, *errormsg;
+	char *query, *errormsg = NULL;
 	int error;
 
 	query = sqlite_mprintf(sql_add_cdr_entry, cdr_table, cdr->clid,
@@ -679,18 +705,19 @@
 
 	RES_CONFIG_SQLITE_BEGIN
 		error = sqlite_exec(db, query, NULL, NULL, &errormsg);
-	RES_CONFIG_SQLITE_END(error)
+	RES_CONFIG_SQLITE_END(error, errormsg)
 
 	ast_mutex_unlock(&mutex);
 
 	sqlite_freemem(query);
 
 	if (error) {
-		ast_log(LOG_ERROR, "%s\n", errormsg);
+		ast_log(LOG_ERROR, "%s\n", RES_CONFIG_SQLITE_ERRORMSG(errormsg, error));
 		sqlite_freemem(errormsg);
 		return 1;
 	}
 
+	sqlite_freemem(errormsg);
 	return 0;
 }
 
@@ -757,7 +784,7 @@
 	struct ast_config *cfg, struct ast_flags flags, const char *suggested_incl, const char *who_asked)
 {
 	struct cfg_entry_args args;
-	char *query, *errormsg;
+	char *query, *errormsg = NULL;
 	int error;
 
 	if (!config_table) {
@@ -786,7 +813,7 @@
 
 	RES_CONFIG_SQLITE_BEGIN
 		error = sqlite_exec(db, query, add_cfg_entry, &args, &errormsg);
-	RES_CONFIG_SQLITE_END(error)
+	RES_CONFIG_SQLITE_END(error, errormsg)
 
 	ast_mutex_unlock(&mutex);
 
@@ -794,11 +821,12 @@
 	sqlite_freemem(query);
 
 	if (error) {
-		ast_log(LOG_ERROR, "%s\n", errormsg);
+		ast_log(LOG_ERROR, "%s\n", RES_CONFIG_SQLITE_ERRORMSG(errormsg, error));
 		sqlite_freemem(errormsg);
 		return NULL;
 	}
 
+	sqlite_freemem(errormsg);
 	return cfg;
 }
 
@@ -871,7 +899,7 @@
 
 static struct ast_variable * realtime_handler(const char *database, const char *table, va_list ap)
 {
-	char *query, *errormsg, *op, *tmp_str;
+	char *query, *errormsg = NULL, *op, *tmp_str;
 	struct rt_cfg_entry_args args;
 	const char **params, **vals;
 	size_t params_count;
@@ -942,19 +970,20 @@
 
 	RES_CONFIG_SQLITE_BEGIN
 		error = sqlite_exec(db, query, add_rt_cfg_entry, &args, &errormsg);
-	RES_CONFIG_SQLITE_END(error)
+	RES_CONFIG_SQLITE_END(error, errormsg)
 
 	ast_mutex_unlock(&mutex);
 
 	sqlite_freemem(query);
 
 	if (error) {
-		ast_log(LOG_WARNING, "%s\n", errormsg);
+		ast_log(LOG_WARNING, "%s\n", RES_CONFIG_SQLITE_ERRORMSG(errormsg, error));
 		sqlite_freemem(errormsg);
 		ast_variables_destroy(args.var);
 		return NULL;
 	}
 
+	sqlite_freemem(errormsg);
 	return args.var;
 }
 
@@ -1009,7 +1038,7 @@
 static struct ast_config *realtime_multi_handler(const char *database,
 	const char *table, va_list ap)
 {
-	char *query, *errormsg, *op, *tmp_str, *initfield;
+	char *query, *errormsg = NULL, *op, *tmp_str, *initfield;
 	struct rt_multi_cfg_entry_args args;
 	const char **params, **vals;
 	struct ast_config *cfg;
@@ -1107,7 +1136,7 @@
 
 	RES_CONFIG_SQLITE_BEGIN
 		error = sqlite_exec(db, query, add_rt_multi_cfg_entry, &args, &errormsg);
-	RES_CONFIG_SQLITE_END(error)
+	RES_CONFIG_SQLITE_END(error, errormsg)
 
 	ast_mutex_unlock(&mutex);
 
@@ -1115,19 +1144,20 @@
 	ast_free(initfield);
 
 	if (error) {
-		ast_log(LOG_WARNING, "%s\n", errormsg);
+		ast_log(LOG_WARNING, "%s\n", RES_CONFIG_SQLITE_ERRORMSG(errormsg, error));
 		sqlite_freemem(errormsg);
 		ast_config_destroy(cfg);
 		return NULL;
 	}
 
+	sqlite_freemem(errormsg);
 	return cfg;
 }
 
 static int realtime_update_handler(const char *database, const char *table,
 	const char *keyfield, const char *entity, va_list ap)
 {
-	char *query, *errormsg, *tmp_str;
+	char *query, *errormsg = NULL, *tmp_str;
 	const char **params, **vals;
 	size_t params_count;
 	int error, rows_num;
@@ -1187,7 +1217,7 @@
 
 	RES_CONFIG_SQLITE_BEGIN
 		error = sqlite_exec(db, query, NULL, NULL, &errormsg);
-	RES_CONFIG_SQLITE_END(error)
+	RES_CONFIG_SQLITE_END(error, errormsg)
 
 	if (!error)
 		rows_num = sqlite_changes(db);
@@ -1199,16 +1229,16 @@
 	sqlite_freemem(query);
 
 	if (error) {
-		ast_log(LOG_WARNING, "%s\n", errormsg);
-		sqlite_freemem(errormsg);
+		ast_log(LOG_WARNING, "%s\n", RES_CONFIG_SQLITE_ERRORMSG(errormsg, error));
 	}
 
+	sqlite_freemem(errormsg);
 	return rows_num;
 }
 
 static int realtime_store_handler(const char *database, const char *table, va_list ap)
 {
-	char *errormsg, *tmp_str, *tmp_keys = NULL, *tmp_keys2 = NULL, *tmp_vals = NULL, *tmp_vals2 = NULL;
+	char *errormsg = NULL, *tmp_str, *tmp_keys = NULL, *tmp_keys2 = NULL, *tmp_vals = NULL, *tmp_vals2 = NULL;
 	const char **params, **vals;
 	size_t params_count;
 	int error, rows_id;
@@ -1280,7 +1310,7 @@
 
 	RES_CONFIG_SQLITE_BEGIN
 		error = sqlite_exec(db, tmp_str, NULL, NULL, &errormsg);
-	RES_CONFIG_SQLITE_END(error)
+	RES_CONFIG_SQLITE_END(error, errormsg)
 
 	if (!error) {
 		rows_id = sqlite_last_insert_rowid(db);
@@ -1293,17 +1323,17 @@
 	sqlite_freemem(tmp_str);
 
 	if (error) {
-		ast_log(LOG_WARNING, "%s\n", errormsg);
-		sqlite_freemem(errormsg);
+		ast_log(LOG_WARNING, "%s\n", RES_CONFIG_SQLITE_ERRORMSG(errormsg, error));
 	}
 
+	sqlite_freemem(errormsg);
 	return rows_id;
 }
 
 static int realtime_destroy_handler(const char *database, const char *table,
 	const char *keyfield, const char *entity, va_list ap)
 {
-	char *query, *errormsg, *tmp_str;
+	char *query, *errormsg = NULL, *tmp_str;
 	const char **params, **vals;
 	size_t params_count;
 	int error, rows_num;
@@ -1358,7 +1388,7 @@
 
 	RES_CONFIG_SQLITE_BEGIN
 		error = sqlite_exec(db, query, NULL, NULL, &errormsg);
-	RES_CONFIG_SQLITE_END(error)
+	RES_CONFIG_SQLITE_END(error, errormsg)
 
 	if (!error)
 		rows_num = sqlite_changes(db);
@@ -1370,10 +1400,10 @@
 	sqlite_freemem(query);
 
 	if (error) {
-		ast_log(LOG_WARNING, "%s\n", errormsg);
-		sqlite_freemem(errormsg);
+		ast_log(LOG_WARNING, "%s\n", RES_CONFIG_SQLITE_ERRORMSG(errormsg, error));
 	}
 
+	sqlite_freemem(errormsg);
 	return rows_num;
 }
 
@@ -1431,7 +1461,7 @@
 
 static int load_module(void)
 {
-	char *errormsg;
+	char *errormsg = NULL;
 	int error;
 
 	db = NULL;
@@ -1446,11 +1476,13 @@
 		return AST_MODULE_LOAD_DECLINE;
 
 	if (!(db = sqlite_open(dbfile, 0660, &errormsg))) {
-		ast_log(LOG_ERROR, "%s\n", errormsg);
+		ast_log(LOG_ERROR, "%s\n", RES_CONFIG_SQLITE_ERRORMSG(errormsg, error));
 		sqlite_freemem(errormsg);
 		unload_module();
 		return 1;
 	}
+	sqlite_freemem(errormsg);
+	errormsg = NULL;
 
 	ast_config_engine_register(&sqlite_engine);
 
@@ -1474,7 +1506,7 @@
 
 		RES_CONFIG_SQLITE_BEGIN
 			error = sqlite_exec(db, query, NULL, NULL, &errormsg);
-		RES_CONFIG_SQLITE_END(error)
+		RES_CONFIG_SQLITE_END(error, errormsg)
 
 		sqlite_freemem(query);
 
@@ -1483,13 +1515,14 @@
 			 * Unexpected error.
 			 */
 			if (error != SQLITE_ERROR) {
-				ast_log(LOG_ERROR, "%s\n", errormsg);
+				ast_log(LOG_ERROR, "%s\n", RES_CONFIG_SQLITE_ERRORMSG(errormsg, error));
 				sqlite_freemem(errormsg);
 				unload_module();
 				return 1;
 			}
+			sqlite_freemem(errormsg);
+			errormsg = NULL;
 
-			sqlite_freemem(errormsg);
 			query = sqlite_mprintf(sql_create_cdr_table, cdr_table);
 
 			if (!query) {
@@ -1502,18 +1535,21 @@
 
 			RES_CONFIG_SQLITE_BEGIN
 				error = sqlite_exec(db, query, NULL, NULL, &errormsg);
-			RES_CONFIG_SQLITE_END(error)
+			RES_CONFIG_SQLITE_END(error, errormsg)
 
 			sqlite_freemem(query);
 
 			if (error) {
-				ast_log(LOG_ERROR, "%s\n", errormsg);
+				ast_log(LOG_ERROR, "%s\n", RES_CONFIG_SQLITE_ERRORMSG(errormsg, error));
 				sqlite_freemem(errormsg);
 				unload_module();
 				return 1;
 			}
 		}
 
+		sqlite_freemem(errormsg);
+		errormsg = NULL;
+
 		error = ast_cdr_register(RES_CONFIG_SQLITE_NAME, RES_CONFIG_SQLITE_DESCRIPTION, cdr_handler);
 
 		if (error) {