Fix issue 15261: Crash in history::TextDatabase::GetTextMatches...

third_party/sqlite/ext/fts3/fts3.c

 /*
 ** 2006 Oct 10
 **
 ** The author disclaims copyright to this source code.  In place of
 ** a legal notice, here is a blessing:
 **
 **    May you do good and not evil.
 **    May you find forgiveness for yourself and forgive others.
 **    May you share freely, never taking more than you give.
 **
@@ skipping 312 matching lines @@
 */
 /* TODO(shess) The snippet-generation code should be using the
 ** tokenizer-generated tokens rather than doing its own local
 ** tokenization.
 */
 /* TODO(shess) Is __isascii() a portable version of (c&0x80)==0? */
 static int safe_isspace(char c){
   return (c&0x80)==0 ? isspace(c) : 0;
 }
 static int safe_tolower(char c){
-  return (c&0x80)==0 ? tolower(c) : c;
+  return (c>='A' && c<='Z') ? (c-'A'+'a') : c;
 }
 static int safe_isalnum(char c){
   return (c&0x80)==0 ? isalnum(c) : 0;
 }
 
 typedef enum DocListType {
   DL_DOCIDS,              /* docids only */
   DL_POSITIONS,           /* docids + positions */
   DL_POSITIONS_OFFSETS    /* docids + positions + offsets */
 } DocListType;
@@ skipping 6863 matching lines @@
   sqlite3 *db, 
   char **pzErrMsg,
   const sqlite3_api_routines *pApi
 ){
   SQLITE_EXTENSION_INIT2(pApi)
   return sqlite3Fts3Init(db);
 }
 #endif
 
 #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */