#1759 Fix terrain related material selection

1. Properly register blank material in LLGLTFMaterialList. This means that it will be regularly checked, but shouldn't be an issue.
2. Fix texture picker using IMG_WHITE for blank materials

Author: akleshchev

indra/newview/gltfscenemanager.cpp

@@ -716,7 +716,7 @@ void GLTFSceneManager::render(Asset& asset, U8 variant)
             }
             else
             {
-                LLFetchedGLTFMaterial::sDefault.bind();
+                LLFetchedGLTFMaterial::sDefault->bind();
                 LLGLSLShader::sCurBoundShaderPtr->uniform1i(LLShaderMgr::GLTF_MATERIAL_ID, -1);
             }
 

indra/newview/llfetchedgltfmaterial.cpp

@@ -35,7 +35,7 @@
 #include "pipeline.h"
 
 //static
-LLFetchedGLTFMaterial LLFetchedGLTFMaterial::sDefault;
+LLPointer<LLFetchedGLTFMaterial> LLFetchedGLTFMaterial::sDefault(new LLFetchedGLTFMaterial());
 
 LLFetchedGLTFMaterial::LLFetchedGLTFMaterial()
     : LLGLTFMaterial()

indra/newview/llfetchedgltfmaterial.h

@@ -71,7 +71,7 @@ class LLFetchedGLTFMaterial: public LLGLTFMaterial
     std::set<LLTextureEntry*> mTextureEntires;
 
     // default material for when assets don't have one
-    static LLFetchedGLTFMaterial sDefault;
+    static LLPointer<LLFetchedGLTFMaterial> sDefault;
 protected:
     // Lifetime management
 

indra/newview/llgltfmateriallist.cpp

@@ -617,6 +617,15 @@ void LLGLTFMaterialList::onAssetLoadComplete(const LLUUID& id, LLAssetType::ETyp
     }
 }
 
+LLGLTFMaterialList::LLGLTFMaterialList()
+{
+    LLFetchedGLTFMaterial::sDefault->materialBegin();
+    LLFetchedGLTFMaterial::sDefault->materialComplete(true);
+    // Hack:
+    // Saved by Id instead of BLANK_MATERIAL_ASSET_ID because constants aren't initialized.
+    addMaterial(LLUUID("968cbad0-4dad-d64e-71b5-72bf13ad051a"), LLFetchedGLTFMaterial::sDefault);
+}
+
 LLFetchedGLTFMaterial* LLGLTFMaterialList::getMaterial(const LLUUID& id)
 {
     LL_PROFILE_ZONE_SCOPED;

indra/newview/llgltfmateriallist.h

@@ -40,7 +40,7 @@ class LLGLTFOverrideCacheEntry;
 class LLGLTFMaterialList
 {
 public:
-    LLGLTFMaterialList() {}
+    LLGLTFMaterialList();
 
 
     LLFetchedGLTFMaterial* getMaterial(const LLUUID& id);

indra/newview/lltexturectrl.cpp

@@ -1704,10 +1704,16 @@ LLTextureCtrl::LLTextureCtrl(const LLTextureCtrl::Params& p)
     mDefaultImageName(p.default_image_name),
     mFallbackImage(p.fallback_image)
 {
-
-    // Default of defaults is white image for diff tex
-    //
-    setBlankImageAssetID(IMG_WHITE);
+    if (mInventoryPickType == PICK_MATERIAL)
+    {
+        setBlankImageAssetID(BLANK_MATERIAL_ASSET_ID);
+    }
+    else
+    {
+        // Default of defaults is white image for diff tex
+        //
+        setBlankImageAssetID(IMG_WHITE);
+    }
 
     setAllowNoTexture(p.allow_no_texture);
     setCanApplyImmediately(p.can_apply_immediately);