Broken links report only looks at published pages

[chillu]

Overview

When linking between internal pages, and then deleting the link target, the linking page is marked with HasBrokenLinks=1 upon save. This happens behind the scenes, and only in the draft stage. The "broken links" report only looks at the live stage by default, so doesn't pick up the broken link until this page is republished. Since there's no actual changes by content authors, this republishing is counter-intuitive.

Steps

• Create Page A, publish
• Create Page B, add link to Page A, publish
• Delete Page A
• Open "broken links report"
• Expected: Lists Page B
• Actual: Doesn't list Page B

Notes

• This might be resolved by not writing HasBrokenLinks=1 to draft only - we should do one pass for draft, and one pass for live mode (since they might have different content).
• Related: Broken links cause page to be modified without actual content modifications

/cc @silverstripeux (talked to Paul this morning)