Fixes (more or less) random SEGFAULT upon invoking script_command().

git-svn-id: svn://svn.berlios.de/openocd/trunk@1156 b42882b7-edfa-0310-969c-e2dbd0fdcd60

diff --git a/src/helper/command.c b/src/helper/command.c
index d47203ca0060fcda7a331d2abac89a8777bbdeb2..9ca64dd2df37bb50ca3934b4bea5b5453baf9940 100644 (file)
--- a/src/helper/command.c
+++ b/src/helper/command.c
@@ -64,7 +64,6 @@ static void tcl_output(void *privData, const char *file, int line, const char *f
 
 extern command_context_t *global_cmd_ctx;
 
-
 static int script_command(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 {
        /* the private data is stashed in the interp structure */
@@ -75,10 +74,20 @@ static int script_command(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
        int nwords;
        char **words;
 
+       /* DANGER!!!! be careful what we invoke here, since interp->cmdPrivData might
+        * get overwritten by running other Jim commands! Treat it as an
+        * emphemeral global variable that is used in lieu of an argument
+        * to the fn and fish it out manually.
+        */
+       c = interp->cmdPrivData;
+       if (c==NULL)
+       {
+               LOG_ERROR("BUG: interp->cmdPrivData==NULL");
+               return JIM_ERR;
+       }
        target_call_timer_callbacks_now();
        LOG_USER_N("%s", ""); /* Keep GDB connection alive*/
 
-       c = interp->cmdPrivData;
        LOG_DEBUG("script_command - %s", c->name);
 
        words = malloc(sizeof(char *) * argc);