[Backport branch-7-6] Improved initial check on generating reference maps, avoid crash with label styles (symbol errors), removed dead code. (#6298)

* Fixes for a couple of things I ran into when doing an upgrade on app

* Update mapraster.c

Resolve merge conflict.

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Steve Lime <steve.lime@state.mn.us>

Author: 3 people

mapdraw.c

@@ -2837,7 +2837,7 @@ int computeMarkerBounds(mapObj *map, pointObj *annopoint, textSymbolObj *ts, lab
       double aox,aoy;
       symbolObj *symbol = map->symbolset.symbol[style->symbol];
       if(msGetMarkerSize(map, style, &sx, &sy, ts->scalefactor) != MS_SUCCESS)
-        return MS_FALSE;
+        return -1; /* real error, different from MS_FALSE, return -1 so we can trap it */
       if(style->angle) {
         pointObj *point = poly->poly->point;
         point[0].x = sx / 2.0;
@@ -3125,6 +3125,7 @@ int msDrawLabelCache(mapObj *map, imageObj *image)
                   break; /* the marker collided, break from multi-label loop */
                 }
               }
+              if(have_label_marker == -1) return MS_FAILURE; /* error occured (symbol not found, etc...) */
 
               if(textSymbolPtr->annotext) {
                 /*

mapfile.c

@@ -6637,17 +6637,6 @@ int msUpdateMapFromURL(mapObj *map, char *variable, char *string)
   switch(msyylex()) {
     case(MAP):
       switch(msyylex()) {
-        case(CONFIG): {
-          char *key=NULL, *value=NULL;
-          if((getString(&key) != MS_FAILURE) && (getString(&value) != MS_FAILURE)) {
-            msSetConfigOption( map, key, value );
-            free( key );
-            key=NULL;
-            free( value );
-            value=NULL;
-          }
-        }
-        break;
         case(EXTENT):
           msyystate = MS_TOKENIZE_URL_STRING;
           msyystring = string;

mapraster.c

@@ -984,16 +984,22 @@ imageObj *msDrawReferenceMap(mapObj *map)
   char szPath[MS_MAXPATHLEN];
   int status = MS_SUCCESS;
 
-  imageObj   *image = NULL;
+  imageObj *image = NULL;
   styleObj style;
 
+  /* check to see if we have enough information to actually proceed */
+  if(!map->reference.image || map->reference.height == 0 || map->reference.width == 0) {
+    msSetError(MS_MISCERR, "Reference map configuration error.", "msDrawReferenceMap()");
+    return NULL;
+  }
 
   rendererVTableObj *renderer = MS_MAP_RENDERER(map);
   rasterBufferObj *refImage = (rasterBufferObj*)calloc(1,sizeof(rasterBufferObj));
   MS_CHECK_ALLOC(refImage, sizeof(rasterBufferObj), NULL);
 
   if(MS_SUCCESS != renderer->loadImageFromFile(msBuildPath(szPath, map->mappath, map->reference.image),refImage)) {
-    msSetError(MS_MISCERR,"error loading reference image %s","msDrawREferenceMap()",szPath);
+    msSetError(MS_MISCERR,"Error loading reference image %s.","msDrawReferenceMap()",szPath);
+    free(refImage);
     return NULL;
   }