Fix error in mat4x2(scalar) construction.

src/OpenGL/compiler/parseConst.cpp

@@ -199,19 +199,26 @@ void TConstTraverser::visitConstantUnion(TIntermConstantUnion* node)
 			}
 		} else {  // for matrix constructors
 			int count = 0;
-			int element = index;
-			for(size_t i = index; i < totalSize; i++) {
-				if (i >= instanceSize)
-					return;
-				if (element - i == 0 || (i - element) % (matrixRows + 1) == 0 )
-					leftUnionArray[i].cast(basicType, rightUnionArray[0]);
-				else
-					leftUnionArray[i].setFConst(0.0f);
-
-				(index)++;
-
-				if (node->getType().getObjectSize() > 1)
+			if (node->getType().getObjectSize() == 1) {
+				// Synthesize a diagonal matrix from the provided scalar.
+				int matrixCols = node->getType().getNominalSize();
+				for (int c = 0; c < matrixCols; ++c) {
+					for (int r = 0; r < matrixRows; ++r) {
+						if (r == c)
+							leftUnionArray[index].cast(basicType, rightUnionArray[0]);
+						else
+							leftUnionArray[index].setFConst(0.0);
+						(index)++;
+					}
+				}
+			} else {
+				// Construct a matrix from the provided components.
+				for (size_t i = index; i < totalSize; i++) {
+					if (i >= instanceSize)
+						return;
+					leftUnionArray[i].cast(basicType, rightUnionArray[count]);
 					count++;
+				}
 			}
 		}
 	}