better error handling when source command targets a directory

Author: MohamedM216

client/mysql.cc

@@ -4531,6 +4531,7 @@ static int com_source(String *, char *line)
   STATUS old_status;
   FILE *sql_file;
   my_bool save_ignore_errors;
+  MY_STAT stat_info;
 
   if (status.sandbox)
     return put_info("Not allowed in the sandbox mode", INFO_ERROR, 0);
@@ -4557,6 +4558,16 @@ static int com_source(String *, char *line)
     return put_info(buff, INFO_ERROR, 0);
   }
 
+  /* verify it's not a directory */
+  if (my_fstat(fileno(sql_file), &stat_info, MYF(0)) == 0 && 
+      MY_S_ISDIR(stat_info.st_mode))
+  {
+    my_fclose(sql_file, MYF(0));
+    char buff[FN_REFLEN+60];
+    sprintf(buff, "'%s' is a directory, not a file", source_name);
+    return put_info(buff, INFO_ERROR, 0);
+  }
+
   if (!(line_buff= batch_readline_init(MAX_BATCH_BUFFER_SIZE, sql_file)))
   {
     my_fclose(sql_file,MYF(0));