git log -L:function_name:file_name can be used to get the log of all commits that touched a specific function. But it always shows the content/diff of the commit as if -p option was applied.
I have tried to several different options to the command like --oneline, --abbrev-commit, -U0 but they just remove a few lines and still print a lot of commit content.
How can I get a one-line summary?
As indicated in the doc, only --no-patch achieves what you want. Other diff format options are disabled with -L
Implies
--patch. Patch output can be suppressed using--no-patch, but other diff formats (namely--raw,--numstat,--shortstat,--dirstat,--summary,--name-only,--name-status,--check) are not currently implemented.