after giving an error message.
(merge 3bb0923f06 ps/contains-id-error-message later to maint).
- * "diff-highlight" filter (in contrib/) learned to undertand "git log
+ * "diff-highlight" filter (in contrib/) learned to understand "git log
--graph" output better.
(merge 4551fbba14 jk/diff-highlight-graph-fix later to maint).