Hi Zack On 23/11/2022 20:17, Zack Weinberg wrote:
I’m attempting to have my blog, which is a static site generated from a bunch of Markdown files stored in git, automatically pull the the most recent modification date for each page out of the git history. The idea is to use ‘git log --follow --pretty=tformat:'%ct' <file>‘ on each file and then use the oldest reported timestamp as the creation date and the newest reported timestamp as the last modification date. But there’s a catch: there are commits I want to ignore in this calculation, such as mechanical changes applied to the entire site. And this brings me to the bug: --invert-grep doesn’t work correctly when the --grep regex is sufficiently complicated. Here's the complete set of commits that modified an example file: $ git log --follow --pretty=tformat:'%ct %s' \ src/posts/uncat/unearthed-arcana-music-division.md 1668545053 Begin restoring the site structure. 1668545051 Reorganize directory tree prior to setting up Metalsmith 1668545032 Mechanically convert Pandoc to standard YAML metadata delimiters. 1610735533 Mechanically convert to properly delimited YAML metadata. 1417101173 Correct slug for Uncategorized. 1417050416 The Great Dead and Moved Link Cleanup of 2014. 1416938128 Use category_meta plugin to fix category slugs. 1416763607 Initial import of content and Pelican skeleton. And here's an application of --grep that prints only the commits I _don't_ want: $ git log --follow -E --pretty=tformat:'%ct %s' \ --grep='^(Mechanically convert|Begin restoring the site structure|Reorganize directory tree)' \ src/posts/uncat/unearthed-arcana-music-division.md 1668545053 Begin restoring the site structure. 1668545051 Reorganize directory tree prior to setting up Metalsmith 1668545032 Mechanically convert Pandoc to standard YAML metadata delimiters. 1610735533 Mechanically convert to properly delimited YAML metadata. Theoretically, adding --invert-grep to that should make it print the commits I do want, but instead it prints nothing at all:
I think the problem is that you are excluding the commit that renames the file and that stops --follow from following the rename. See below for a simple reproduction using git's test suite. I'm afraid I'm not familiar with the --follow code so I've no idea how to fix this.
Best Wishes Phillip ---- >8 ---- #!/bin/sh test_description='Demonstrate `git log --follow --grep` failure' . ./test-lib.sh test_expect_failure '--grep breaks --follow' ' test_commit first file-a "$(seq 1 100)" && git rm file-a && test_commit second file-b "$(seq 2 101)" && test_commit third file-b "$(seq 3 102)" && git log --follow --grep "^first" file-b >actual && git log first >expect && test_cmp expect actual ' test_expect_success '--grep breaks --follow' ' git log --follow -E --grep "^(first|second)" file-b >actual && git log second >expect && test_cmp expect actual ' test_done
