Ticket #8471: gobega_crash.patch

gob/goblin.cpp

@@ -2387 +2387 @@
         int16 layer;
         int16 state;
         int32 *retVarPtr;
+        bool objDescSet = false;
 
         retVarPtr = (int32 *)VAR_ADDRESS(59);
 
@@ -2395 +2396 @@
         if (cmd > 0 && cmd < 17) {
                 extraData = inter_load16();
                 objDesc = gob_objects[extraData];
+                objDescSet = true;
                 extraData = inter_load16();
         }
 
         if (cmd > 90 && cmd < 107) {
                 extraData = inter_load16();
                 objDesc = gob_goblins[extraData];
+                objDescSet = true;
                 extraData = inter_load16();
                 cmd -= 90;
         }
@@ -2408 +2411 @@
         if (cmd > 110 && cmd < 128) {
                 extraData = inter_load16();
                 objDesc = gob_goblins[extraData];
+                objDescSet = true;
                 cmd -= 90;
         } else if (cmd > 20 && cmd < 38) {
                 extraData = inter_load16();
                 objDesc = gob_objects[extraData];
+                objDescSet = true;
         }
 
-        if (cmd < 40 && objDesc == 0)
+/*
+        NB: The original gobliiins engine did not initialize the objDesc
+        variable, so we manually check if objDesc is properly set before
+        checking if it is zero. If it was not set, we do not return. This
+        fixes a crash in the EGA version if the life bar is depleted, because
+        gob_interFunc is called multiple times with cmd == 39.
+        Bug #1324814
+*/
+
+
+        if (cmd < 40 && objDescSet && objDesc == 0)
                 return;
 
         debug(5, "cmd = %d", cmd);