diff options
| -rw-r--r-- | dom/html/HTMLCanvasElement.cpp | 28 |
1 files changed, 17 insertions, 11 deletions
diff --git a/dom/html/HTMLCanvasElement.cpp b/dom/html/HTMLCanvasElement.cpp index a01795d9e..4b5deab18 100644 --- a/dom/html/HTMLCanvasElement.cpp +++ b/dom/html/HTMLCanvasElement.cpp @@ -552,17 +552,23 @@ HTMLCanvasElement::CopyInnerTo(Element* aDest) HTMLCanvasElement* dest = static_cast<HTMLCanvasElement*>(aDest); dest->mOriginalCanvas = this; - nsCOMPtr<nsISupports> cxt; - dest->GetContext(NS_LITERAL_STRING("2d"), getter_AddRefs(cxt)); - RefPtr<CanvasRenderingContext2D> context2d = - static_cast<CanvasRenderingContext2D*>(cxt.get()); - if (context2d && !mPrintCallback) { - CanvasImageSource source; - source.SetAsHTMLCanvasElement() = this; - ErrorResult err; - context2d->DrawImage(source, - 0.0, 0.0, err); - rv = err.StealNSResult(); + // We make sure that the canvas is not zero sized since that would cause + // the DrawImage call below to return an error, which would cause printing + // to fail. + nsIntSize size = GetWidthHeight(); + if (size.height > 0 && size.width > 0) { + nsCOMPtr<nsISupports> cxt; + dest->GetContext(NS_LITERAL_STRING("2d"), getter_AddRefs(cxt)); + RefPtr<CanvasRenderingContext2D> context2d = + static_cast<CanvasRenderingContext2D*>(cxt.get()); + if (context2d && !mPrintCallback) { + CanvasImageSource source; + source.SetAsHTMLCanvasElement() = this; + ErrorResult err; + context2d->DrawImage(source, + 0.0, 0.0, err); + rv = err.StealNSResult(); + } } } return rv; |