External link(s) in JavaDoc not working

[msgilligan]

I found at least one external link in the JavaDoc -- the BIP 32 standard hyperlink in the first main paragraph of the DeterministicKeyChain page -- that fails to load with the following error in Chrome:

about:blank:1 Refused to display 'https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki' in a frame because an ancestor violates the following Content Security Policy directive: "frame-ancestors 'none'".

The problem is related to Content Security Policy in frames mode and the link works correctly when the containing page is viewed as a standalone page.

It is failing in both Chrome 74.0.3729.16 an Safari 12.1 on macOS 10.14.4.

[schildbach]

Indeed, this fails under Firefox too.

[msgilligan]

One solution to this might be to build the official release of the javadoc with JDK 11 and set the html5 option. I could make a PR to conditionally apply the html5 option when available (I did this in ConsensusJ.) One nice thing about the html5 option is that it also adds a (client-side) search option.

Update: I built the javadoc with JDK 11 and it generated html5 by default.

[schildbach]

I think that sounds like a good solution. Feel free to PR.

[msgilligan]

Actually, I started working on a PR and found that no changes to Gradle config were needed, if we just build the javadocs with JDK11 we'll get HTML5.

[msgilligan]

This should be fixed now that we're building with JDK 11 and publishing HTML5 JavaDoc

[schildbach]

Note that JDK 11 is not yet the requirement for building. If we want to go this step for 0.17, I think we should do so as early as possible in the cycle.

[msgilligan]

My main concern in this issue is that we didn't want broken links in our published JavaDoc. For this purpose we are concerned with the JDK version used in the official build (which is now JDK 11) not the minimum JDK required for a build.

But I do agree that the update to require JDK 11 for the build should be made early in the 0.17 cycle.