final preparation

sqlite3.wit

@@ -1,4 +1,4 @@
-(@interface it_version "0.19.0"
+(@interface it_version "0.19.0")
 
 ;; Types
 (@interface type (func

src/legacy.c

@@ -35,7 +35,7 @@ void sqlite3_exec_(
   sqlite3_callback xCallback, /* Invoke this callback routine */
   void *pArg                  /* First argument to xCallback() */
 ) __EXPORT_NAME(sqlite3_exec) {
-  zSql[zSql_len] = '\x00';
+  zSql = handle_input_string(zSql, zSql_len);
 
   char *pzErrMsg = 0;
   const int ret_code = sqlite3_exec(db, zSql, xCallback, pArg, &pzErrMsg);

src/main.c

@@ -3443,9 +3443,8 @@ void sqlite3_open_v2_(
   char *zVfs,             /* Name of VFS module to use */
   int zVfs_len
 ) __EXPORT_NAME(sqlite3_open_v2) {
-  // this strings were allocated by the allocate function that allocates 1 byte more for null character
-  filename[filename_len] = '\x00';
-  zVfs[zVfs_len] = '\x00';
+  filename = handle_input_string(filename, filename_len);
+  zVfs = handle_input_string(zVfs, zVfs_len);
 
   sqlite3 *ppDb;
 

src/sqliteInt.h

@@ -4913,6 +4913,8 @@ void add_object_to_release(void *object);
 
 void set_result_ptr(void *ptr);
 void set_result_size(int size);
+
+char *handle_input_string(char *str, int len);
 #endif
 
 #endif /* SQLITEINT_H */

src/wrapper.c

@@ -43,6 +43,17 @@ void *get_result_ptr() {
   return RESULT_PTR;
 }
 
+char *handle_input_string(char *str, int len) {
+  if (len == 0) {
+    free(str);
+    return NULL;
+  }
+
+  // this strings are supposed to be allocated by the allocate function, which allocates 1 byte more for null character
+  str[len] = '\x00';
+  return str;
+}
+
 int main() {
   // the main purpose of this empty main is to initialize WASI subsystem
   return 0;