Bug 636002 - better messages about attrib index validation - r=jrmuizel, a=joe

content/canvas/src/WebGLContext.h

@@ -440,6 +440,7 @@ protected:
     PRBool ValidateTexFormatAndType(WebGLenum format, WebGLenum type,
                                       PRUint32 *texelSize, const char *info);
     PRBool ValidateDrawModeEnum(WebGLenum mode, const char *info);
+    PRBool ValidateAttribIndex(WebGLuint index, const char *info);
 
     void Invalidate();
     void DestroyResourcesAndContext();

content/canvas/src/WebGLContextGL.cpp

@@ -183,6 +183,9 @@ WebGLContext::BindAttribLocation(nsIWebGLProgram *pobj, WebGLuint location, cons
     if (name.IsEmpty())
         return ErrorInvalidValue("BindAttribLocation: name can't be null or empty");
 
+    if (!ValidateAttribIndex(location, "bindAttribLocation"))
+        return NS_OK;
+
     MakeContextCurrent();
 
     gl->fBindAttribLocation(progname, location, NS_LossyConvertUTF16toASCII(name).get());
@@ -1087,8 +1090,8 @@ WebGLContext::DepthRange(WebGLfloat zNear, WebGLfloat zFar)
 NS_IMETHODIMP
 WebGLContext::DisableVertexAttribArray(WebGLuint index)
 {
-    if (index > mAttribBuffers.Length())
-        return ErrorInvalidValue("DisableVertexAttribArray: index out of range");
+    if (!ValidateAttribIndex(index, "disableVertexAttribArray"))
+        return NS_OK;
 
     MakeContextCurrent();
 
@@ -1452,8 +1455,8 @@ NS_IMETHODIMP WebGLContext::Disable(WebGLenum cap)
 NS_IMETHODIMP
 WebGLContext::EnableVertexAttribArray(WebGLuint index)
 {
-    if (index > mAttribBuffers.Length())
-        return ErrorInvalidValue("EnableVertexAttribArray: index out of range");
+    if (!ValidateAttribIndex(index, "enableVertexAttribArray"))
+        return NS_OK;
 
     MakeContextCurrent();
 
@@ -2512,8 +2515,8 @@ WebGLContext::GetVertexAttrib(WebGLuint index, WebGLenum pname, nsIVariant **ret
 {
     *retval = nsnull;
 
-    if (index >= mAttribBuffers.Length())
-        return ErrorInvalidValue("getVertexAttrib: invalid index");
+    if (!ValidateAttribIndex(index, "getVertexAttrib"))
+        return NS_OK;
 
     nsCOMPtr<nsIWritableVariant> wrval = do_CreateInstance("@mozilla.org/variant;1");
     NS_ENSURE_TRUE(wrval, NS_ERROR_FAILURE);
@@ -2579,8 +2582,8 @@ WebGLContext::GetVertexAttribOffset(WebGLuint index, WebGLenum pname, WebGLuint
 {
     *retval = 0;
 
-    if (index >= mAttribBuffers.Length())
-        return ErrorInvalidValue("getVertexAttribOffset: invalid index");
+    if (!ValidateAttribIndex(index, "getVertexAttribOffset"))
+        return NS_OK;
 
     if (pname != LOCAL_GL_VERTEX_ATTRIB_ARRAY_POINTER)
         return ErrorInvalidEnum("getVertexAttribOffset: bad parameter");
@@ -3873,8 +3876,8 @@ WebGLContext::VertexAttribPointer(WebGLuint index, WebGLint size, WebGLenum type
     // requiredAlignment should always be a power of two.
     WebGLsizei requiredAlignmentMask = requiredAlignment - 1;
 
-    if (index >= mAttribBuffers.Length())
-        return ErrorInvalidValue("VertexAttribPointer: index out of range - %d >= %d", index, mAttribBuffers.Length());
+    if (!ValidateAttribIndex(index, "vertexAttribPointer"))
+        return NS_OK;
 
     if (size < 1 || size > 4)
         return ErrorInvalidValue("VertexAttribPointer: invalid element size");

content/canvas/src/WebGLContextValidate.cpp

@@ -376,6 +376,22 @@ PRBool WebGLContext::ValidateTexFormatAndType(WebGLenum format, WebGLenum type,
     }
 }
 
+PRBool WebGLContext::ValidateAttribIndex(WebGLuint index, const char *info)
+{
+    if (index > mAttribBuffers.Length()) {
+        if (index == WebGLuint(-1)) {
+             ErrorInvalidValue("%s: index -1 is invalid. That probably comes from a getAttribLication() call, "
+                               "where this return value -1 means that the passed name didn't correspond to an active attribute in "
+                               "the specified program.", info);
+        } else {
+             ErrorInvalidValue("%s: index %d is out of range", info, index);
+        }
+        return PR_FALSE;
+    } else {
+        return PR_TRUE;
+    }
+}
+
 PRBool
 WebGLContext::InitAndValidateGL()
 {