Reland of validate uniform block index

third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.cpp

Index: third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.cpp
diff --git a/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.cpp b/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.cpp
index d92a66c0d01553210f24831c756c331b6a5b6c95..9f192c103242e66b772cdba52d88ae38082faf43 100644
--- a/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.cpp
+++ b/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.cpp
@@ -2316,9 +2316,23 @@
     return webContext()->getUniformBlockIndex(objectOrZero(program), uniformBlockName.utf8().data());
 }
 
+bool WebGL2RenderingContextBase::validateUniformBlockIndex(const char* functionName, WebGLProgram* program, GLuint blockIndex)
+{
+    GLint activeUniformBlocks = 0;
+    webContext()->getProgramiv(objectOrZero(program), GL_ACTIVE_UNIFORM_BLOCKS, &activeUniformBlocks);
+    if (blockIndex >= static_cast<GLuint>(activeUniformBlocks)) {
+        synthesizeGLError(GL_INVALID_VALUE, functionName, "invalid uniform block index");
+        return false;
+    }
+    return true;
+}
+
 ScriptValue WebGL2RenderingContextBase::getActiveUniformBlockParameter(ScriptState* scriptState, WebGLProgram* program, GLuint uniformBlockIndex, GLenum pname)
 {
     if (isContextLost() || !validateWebGLObject("getActiveUniformBlockParameter", program))
+        return ScriptValue::createNull(scriptState);
+
+    if (!validateUniformBlockIndex("getActiveUniformBlockParameter", program, uniformBlockIndex))
         return ScriptValue::createNull(scriptState);
 
     switch (pname) {
@@ -2357,6 +2371,9 @@
     if (isContextLost() || !validateWebGLObject("getActiveUniformBlockName", program))
         return String();
 
+    if (!validateUniformBlockIndex("getActiveUniformBlockName", program, uniformBlockIndex))
+        return String();
+
     GLint maxNameLength = -1;
     webContext()->getProgramiv(objectOrZero(program), GL_ACTIVE_UNIFORM_BLOCK_MAX_NAME_LENGTH, &maxNameLength);
     if (maxNameLength <= 0) {
@@ -2373,6 +2390,9 @@
 void WebGL2RenderingContextBase::uniformBlockBinding(WebGLProgram* program, GLuint uniformBlockIndex, GLuint uniformBlockBinding)
 {
     if (isContextLost() || !validateWebGLObject("uniformBlockBinding", program))
+        return;
+
+    if (!validateUniformBlockIndex("uniformBlockBinding", program, uniformBlockIndex))
         return;
 
     webContext()->uniformBlockBinding(objectOrZero(program), uniformBlockIndex, uniformBlockBinding);