X-Git-Url: https://git.distorted.org.uk/~mdw/sgt/puzzles/blobdiff_plain/cb64d2dd666eb5d02c6bfd8dcb151fd0a16196d6..fad9cc36230d773950fb068f2089232101477820:/midend.c

diff --git a/midend.c b/midend.c
index a764c77..df661b5 100644
--- a/midend.c
+++ b/midend.c
@@ -387,37 +387,38 @@ static int midend_really_process_key(midend_data *me, int x, int y, int button)
         me->ourgame->dup_game(me->states[me->statepos - 1].state);
     int special = FALSE, gotspecial = FALSE, ret = 1;
     float anim_time;
+    game_state *s;
+    char *movestr;
+	
+    movestr =
+	me->ourgame->interpret_move(me->states[me->statepos-1].state,
+				    me->ui, me->drawstate, x, y, button);
 
-    if (button == 'n' || button == 'N' || button == '\x0E') {
-	midend_stop_anim(me);
-	midend_new_game(me);
-        midend_redraw(me);
-	goto done;		       /* never animate */
-    } else if (button == 'u' || button == 'u' ||
-               button == '\x1A' || button == '\x1F') {
-	midend_stop_anim(me);
-        special = special(me->states[me->statepos-1].movetype);
-        gotspecial = TRUE;
-	if (!midend_undo(me))
+    if (!movestr) {
+	if (button == 'n' || button == 'N' || button == '\x0E') {
+	    midend_stop_anim(me);
+	    midend_new_game(me);
+	    midend_redraw(me);
+	    goto done;		       /* never animate */
+	} else if (button == 'u' || button == 'u' ||
+		   button == '\x1A' || button == '\x1F') {
+	    midend_stop_anim(me);
+	    special = special(me->states[me->statepos-1].movetype);
+	    gotspecial = TRUE;
+	    if (!midend_undo(me))
+		goto done;
+	} else if (button == 'r' || button == 'R' ||
+		   button == '\x12' || button == '\x19') {
+	    midend_stop_anim(me);
+	    if (!midend_redo(me))
+		goto done;
+	} else if (button == 'q' || button == 'Q' || button == '\x11') {
+	    ret = 0;
+	    goto done;
+	} else
 	    goto done;
-    } else if (button == 'r' || button == 'R' ||
-               button == '\x12' || button == '\x19') {
-	midend_stop_anim(me);
-	if (!midend_redo(me))
-            goto done;
-    } else if (button == 'q' || button == 'Q' || button == '\x11') {
-	ret = 0;
-	goto done;
     } else {
-        game_state *s;
-	char *movestr;
-	
-	movestr =
-            me->ourgame->interpret_move(me->states[me->statepos-1].state,
-					me->ui, me->drawstate, x, y, button);
-	if (!movestr)
-	    s = NULL;
-	else if (!*movestr)
+	if (!*movestr)
 	    s = me->states[me->statepos-1].state;
 	else {
 	    s = me->ourgame->execute_move(me->states[me->statepos-1].state,
@@ -855,6 +856,8 @@ config_item *midend_get_config(midend_data *me, int which, char **wintitle)
 static char *midend_game_id_int(midend_data *me, char *id, int defmode)
 {
     char *error, *par, *desc, *seed;
+    game_params *newcurparams, *newparams, *oldparams1, *oldparams2;
+    int free_params;
 
     seed = strchr(id, '#');
     desc = strchr(id, ':');
@@ -894,18 +897,24 @@ static char *midend_game_id_int(midend_data *me, char *id, int defmode)
         }
     }
 
+    /*
+     * We must be reasonably careful here not to modify anything in
+     * `me' until we have finished validating things. This function
+     * must either return an error and do nothing to the midend, or
+     * return success and do everything; nothing in between is
+     * acceptable.
+     */
+    newcurparams = newparams = oldparams1 = oldparams2 = NULL;
+
     if (par) {
-        game_params *tmpparams;
-        tmpparams = me->ourgame->dup_params(me->params);
-        me->ourgame->decode_params(tmpparams, par);
-        error = me->ourgame->validate_params(tmpparams);
+        newcurparams = me->ourgame->dup_params(me->params);
+        me->ourgame->decode_params(newcurparams, par);
+        error = me->ourgame->validate_params(newcurparams);
         if (error) {
-            me->ourgame->free_params(tmpparams);
+            me->ourgame->free_params(newcurparams);
             return error;
         }
-        if (me->curparams)
-            me->ourgame->free_params(me->curparams);
-        me->curparams = tmpparams;
+        oldparams1 = me->curparams;
 
         /*
          * Now filter only the persistent parts of this state into
@@ -913,16 +922,50 @@ static char *midend_game_id_int(midend_data *me, char *id, int defmode)
          * received a params string in which case the whole lot is
          * persistent.
          */
+        oldparams2 = me->params;
         if (seed || desc) {
-            char *tmpstr = me->ourgame->encode_params(tmpparams, FALSE);
-            me->ourgame->decode_params(me->params, tmpstr);
+            char *tmpstr;
+
+            newparams = me->ourgame->dup_params(me->params);
+
+            tmpstr = me->ourgame->encode_params(newcurparams, FALSE);
+            me->ourgame->decode_params(newparams, tmpstr);
+
             sfree(tmpstr);
         } else {
-            me->ourgame->free_params(me->params);
-            me->params = me->ourgame->dup_params(tmpparams);
+            newparams = me->ourgame->dup_params(newcurparams);
         }
+        free_params = TRUE;
+    } else {
+        newcurparams = me->curparams;
+        newparams = me->params;
+        free_params = FALSE;
     }
 
+    if (desc) {
+        error = me->ourgame->validate_desc(newparams, desc);
+        if (error) {
+            if (free_params) {
+                if (newcurparams)
+                    me->ourgame->free_params(newcurparams);
+                if (newparams)
+                    me->ourgame->free_params(newparams);
+            }
+            return error;
+        }
+    }
+
+    /*
+     * Now we've got past all possible error points. Update the
+     * midend itself.
+     */
+    me->params = newparams;
+    me->curparams = newcurparams;
+    if (oldparams1)
+        me->ourgame->free_params(oldparams1);
+    if (oldparams2)
+        me->ourgame->free_params(oldparams2);
+
     sfree(me->desc);
     sfree(me->privdesc);
     me->desc = me->privdesc = NULL;
@@ -930,10 +973,6 @@ static char *midend_game_id_int(midend_data *me, char *id, int defmode)
     me->seedstr = NULL;
 
     if (desc) {
-        error = me->ourgame->validate_desc(me->params, desc);
-        if (error)
-            return error;
-
         me->desc = dupstr(desc);
         me->genmode = GOT_DESC;
         sfree(me->aux_info);