Give the WMS Layer an option to turn off the 'magic' of changing format and

baseLayer state, since that magic can sometimes be problematic. Patch by
part, cleaned up a bit by me, r=me, (Closes #1980)


git-svn-id: http://svn.openlayers.org/trunk/openlayers@9029 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Layer/WMS.js

@@ -54,7 +54,16 @@ OpenLayers.Layer.WMS = OpenLayers.Class(OpenLayers.Layer.Grid, {
      * but some services want it that way. Default false.
      */
     encodeBBOX: false,
- 
+    
+    /** 
+     * APIProperty: noMagic 
+     * {Boolean} If true, the image format will not be automagicaly switched 
+     *     from image/jpeg to image/png or image/gif when using 
+     *     TRANSPARENT=TRUE. Also isBaseLayer will not changed by the  
+     *     constructor. Default false. 
+     */ 
+    noMagic: false,  
+    
     /**
      * Constructor: OpenLayers.Layer.WMS
      * Create a new WMS layer object
@@ -87,7 +96,7 @@ OpenLayers.Layer.WMS = OpenLayers.Class(OpenLayers.Layer.Grid, {
 
 
         //layer is transparent        
-        if (this.params.TRANSPARENT && 
+        if (!this.noMagic && this.params.TRANSPARENT && 
             this.params.TRANSPARENT.toString().toLowerCase() == "true") {
             
             // unless explicitly set in options, make layer an overlay