diff-tree.c: load notes machinery when required

2020-04-21T01:22:54Z

Since its introduction in 7249e91 (revision.c: support --notes command-line option, 2011-03-29), combining '--notes' with any option that causes us to format notes (e.g., '--pretty', '--format="%N"', etc) results in a failed assertion at runtime. $ git rev-list HEAD | git diff-tree --stdin --pretty=medium --notes commit 8f3d9f354286745c751374f5f1fcafee6b3f3136 git: notes.c:1308: format_display_notes: Assertion `display_notes_trees' failed. Aborted This failure is due to diff-tree not calling 'load_display_notes' to initialize the notes machinery. Ordinarily, this failure isn't triggered, because it requires passing both '--notes' and another of the above mentioned options. In the case of '--pretty', for example, we set 'opt->verbose_header', causing 'show_log()' to eventually call 'format_display_notes()', which expects a non-NULL 'display_note_trees'. Without initializing the notes machinery, 'display_note_trees' remains NULL, and thus triggers an assertion failure. Fix this by initializing the notes machinery after parsing our options, and harden this behavior against regression with a test in t4013. (Note that the added ref in this test requires updating two unrelated tests which use 'log --all', and thus need to learn about the new refs). Reported-by: Jeff King Signed-off-by: Taylor Blau Acked-by: Jeff King Signed-off-by: Junio C Hamano

git/t/t4013/diff.diff-tree_--pretty_--notes_note, branch main

diff-tree.c: load notes machinery when required