engine: this condition should never happen, but mdgetskinmap() can return null...

engine: this condition should never happen, but mdgetskinmap() can return null and we weren't checking it

source/build/src/mdsprite.cpp

@@ -2281,34 +2281,40 @@ static int32_t polymost_md3draw(md3model_t *m, tspriteptr_t tspr)
             //POGOTODO: if we add support for palette indexing on model skins, the texture for the palswap could be setup here
             texunits += 4;
 
-            i = r_detailmapping ? mdloadskin((md2model_t *) m, skinNum, DETAILPAL, surfi) : 0;
-
-            if (i)
+            if ((i = r_detailmapping ? mdloadskin((md2model_t *) m, skinNum, DETAILPAL, surfi) : 0))
             {
-                polymost_useDetailMapping(true);
-
                 auto sk = mdgetskinmap(m, DETAILPAL, skinNum, surfi);
-                f = sk->param;
-                polymost_setupdetailtexture(GL_TEXTURE3, i, (sk->flags& HICR_FORCEFILTER) ? (PTH_HIGHTILE | PTH_FORCEFILTER) : PTH_HIGHTILE);
-
-                glMatrixMode(GL_TEXTURE);
-                glLoadIdentity();
-                glTranslatef(xpanning, ypanning, 1.0f);
-                glScalef(f, f, 1.0f);
-                glMatrixMode(GL_MODELVIEW);
+                
+                if (sk != nullptr)
+                {
+                    polymost_useDetailMapping(true);
+                    polymost_setupdetailtexture(GL_TEXTURE3, i, (sk->flags & HICR_FORCEFILTER) ? (PTH_HIGHTILE | PTH_FORCEFILTER) : PTH_HIGHTILE);
+
+                    f = sk->param;
+                    
+                    glMatrixMode(GL_TEXTURE);
+                    glLoadIdentity();
+                    glTranslatef(xpanning, ypanning, 1.0f);
+                    glScalef(f, f, 1.0f);
+                    glMatrixMode(GL_MODELVIEW);
+                }
+                else VLOG_F(LOG_ENGINE, "polymost_md3draw: detail skin %d has no skinmap", skinNum);
             }
 
-            i = r_glowmapping ? mdloadskin((md2model_t *) m, skinNum, GLOWPAL, surfi) : 0;
-
-            if (i)
+            if ((i = r_glowmapping ? mdloadskin((md2model_t *) m, skinNum, GLOWPAL, surfi) : 0))
             {
-                polymost_useGlowMapping(true);
                 auto sk = mdgetskinmap(m, GLOWPAL, skinNum, surfi);
-                polymost_setupglowtexture(GL_TEXTURE4, i, (sk->flags& HICR_FORCEFILTER) ? (PTH_HIGHTILE | PTH_FORCEFILTER) : PTH_HIGHTILE);
-                glMatrixMode(GL_TEXTURE);
-                glLoadIdentity();
-                glTranslatef(xpanning, ypanning, 1.0f);
-                glMatrixMode(GL_MODELVIEW);
+
+                if (sk != nullptr)
+                {
+                    polymost_useGlowMapping(true);
+                    polymost_setupglowtexture(GL_TEXTURE4, i, (sk->flags & HICR_FORCEFILTER) ? (PTH_HIGHTILE | PTH_FORCEFILTER) : PTH_HIGHTILE);
+                    glMatrixMode(GL_TEXTURE);
+                    glLoadIdentity();
+                    glTranslatef(xpanning, ypanning, 1.0f);
+                    glMatrixMode(GL_MODELVIEW);
+                }
+                else VLOG_F(LOG_ENGINE, "polymost_md3draw: glow skin %d has no skinmap", skinNum);
             }
 
             if (r_vertexarrays)
@@ -2554,7 +2560,7 @@ mdmodel_t *mdload(const char *filnam)
 
         // smuggle the file name into the model struct.
         // head.nam is unused as far as I can tell
-        Bstrncpyz(vm3->head.nam, filnam, sizeof(vm3->head.nam));
+        Bstrncpyz(vm3->head.nam, filnam, sizeof(vm3->head.nam)-1);
 
         md3postload_common(vm3);