WebGLRenderer no longer overwrites texture.image when converting to POT. Fixes #7874.

src/renderers/WebGLRenderer.js

@@ -2922,16 +2922,15 @@ THREE.WebGLRenderer = function ( parameters ) {
 		_gl.pixelStorei( _gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, texture.premultiplyAlpha );
 		_gl.pixelStorei( _gl.UNPACK_ALIGNMENT, texture.unpackAlignment );
 
-		texture.image = clampToMaxSize( texture.image, capabilities.maxTextureSize );
+		var image = clampToMaxSize( texture.image, capabilities.maxTextureSize );
 
-		if ( textureNeedsPowerOfTwo( texture ) && isPowerOfTwo( texture.image ) === false ) {
+		if ( textureNeedsPowerOfTwo( texture ) && isPowerOfTwo( image ) === false ) {
 
-			texture.image = makePowerOfTwo( texture.image );
+			image = makePowerOfTwo( image );
 
 		}
 
-		var image = texture.image,
-		isImagePowerOfTwo = isPowerOfTwo( image ),
+		var isImagePowerOfTwo = isPowerOfTwo( image ),
 		glFormat = paramThreeToGL( texture.format ),
 		glType = paramThreeToGL( texture.type );
 
@@ -3009,7 +3008,7 @@ THREE.WebGLRenderer = function ( parameters ) {
 
 			} else {
 
-				state.texImage2D( _gl.TEXTURE_2D, 0, glFormat, glFormat, glType, texture.image );
+				state.texImage2D( _gl.TEXTURE_2D, 0, glFormat, glFormat, glType, image );
 
 			}