Fix glGetShaderSource conformance

src/libGLESv2/Shader.cpp

@@ -148,7 +148,7 @@ void Shader::getSource(GLsizei bufSize, GLsizei *length, char *source)
 
     if (mSource)
     {
-        while (index < bufSize - 1 && index < (int)strlen(mInfoLog))
+        while (index < bufSize - 1 && index < (int)strlen(mSource))
         {
             source[index] = mSource[index];
             index++;

src/libGLESv2/libGLESv2.cpp

@@ -2171,7 +2171,7 @@ void __stdcall glGetShaderSource(GLuint shader, GLsizei bufsize, GLsizei* length
 
             if (!shaderObject)
             {
-                return error(GL_INVALID_VALUE);
+                return error(GL_INVALID_OPERATION);
             }
 
             shaderObject->getSource(bufsize, length, source);
@@ -2916,7 +2916,7 @@ void __stdcall glShaderSource(GLuint shader, GLsizei count, const char** string,
 
             if (!shaderObject)
             {
-                return error(GL_INVALID_VALUE);
+                return error(GL_INVALID_OPERATION);
             }
 
             shaderObject->setSource(count, string, length);