See bug 1421495, if the page doesn't define a type, we don't pick a preferred icon and end up just using the last defined favicon. We can guess type from the extension, when possible.

The website still has the double <link rel=icon> with no type from bug 1421495, and this fix works for pontoon.

Comment on attachment 8933794 [details] Bug 1422289 - ContentLinkHandler should guess icon type from the extension when type is not defined. https://reviewboard.mozilla.org/r/204728/#review210624 ::: browser/modules/ContentLinkHandler.jsm:141 (Diff revision 1) > + case "image/vnd.microsoft.icon": > + case TYPE_ICO: > + return TYPE_ICO; > + case TYPE_SVG: > + return TYPE_SVG; > + } nit: I think this would be a bit more compact: if (icon.type === "image/vnd.microsoft.icon") { return TYPE_ICO; } if (!icon.type) { let extension... } return icon.type || ""; ::: browser/modules/ContentLinkHandler.jsm:144 (Diff revision 1) > + case TYPE_SVG: > + return TYPE_SVG; > + } > + > + // Use the file extension to guess at a type we're interested in > + let extension = icon.iconUri.filePath.split(".").slice(-1)[0]; .pop()?

Comment on attachment 8933794 [details] Bug 1422289 - ContentLinkHandler should guess icon type from the extension when type is not defined. https://reviewboard.mozilla.org/r/204728/#review210624 > nit: I think this would be a bit more compact: > if (icon.type === "image/vnd.microsoft.icon") { > return TYPE_ICO; > } > if (!icon.type) { > let extension... > } > return icon.type || ""; Combined the type check to the same line as fallback while keeping the extension check as only if there's not a type. There is a slight behavior change of the original patch would check the extension even if there was a type, e.g., `<link type="invalid" href="….ico" />` which might not be desired anyway… ? Although there's also a related issue of someone doing `<link type="image/svg+xml" href="….png" />` which would confuse our selection logic… Also added a test to touch the vnd.microsoft.icon code path. > .pop()? Oh. Duh :p

Pushed by edilee@gmail.com: https://hg.mozilla.org/integration/autoland/rev/87305b25064e ContentLinkHandler should guess icon type from the extension when type is not defined. r=mak