476538 - Make nsSVGUtils::ReportToConsole a one time reporter

Status: NEW

(Core :: SVG, defect)

Description

[Jonathan Watt [:jwatt]]

Far too often in our code we silently handle errors in SVG content and the SVG is rendered in a way that will give little clue to the author as to what they did wrong. To help reduce the number of invalid bug reports that we get, and to help make SVG authoring a less painful experience (and thereby generally increase the popularity of SVG and Mozilla), we really want to be able to flag any content errors to the Error Console.

We have nsSVGUtils::ReportToConsole, but we barely use it since, most of the time, errors are detected while we're performing an operation that will/may be performed over and over again during the lifetime of a page, and we don't want to flood the Error Console with tons of duplicate warnings. Perhaps we can solve this problem by making nsSVGUtils::ReportToConsole a single-shot reporter. It could use the property list on a content node to ensure that the same error message is not reported for a given element more than once.

If we can fix this, we can also fix up the many lines of code where we improperly use NS_ASSERTION, NS_ERROR or NS_WARNING to flag bugs in content.