Previously, only a few characters of the SHA would appear on the preview link
comment posted on the PR. This was usually enough for GitHub to create a link to
the corresponding commit, but it was possible to have collisions with other
commits with the same first characters (which prevented GitHub from identifying
the correct commit and create a link.)
This commit fixes this issue by including the full SHA on the commentso GitHub
can identify the correct commit and create the link. GitHub will automatically
truncate the link text (by default to 7 chars unless more are necessary to
uniquely identify the commit).
George Kalpakas