Merge branch 'jc/patch-id' into maint-2.46

Merge branch 'jc/patch-id' into maint-2.46

The patch parser in "git patch-id" has been tightened to avoid
getting confused by lines that look like a patch header in the log
message.
cf. <Zqh2T_2RLt0SeKF7@tanuki>

* jc/patch-id:
  patch-id: tighten code to detect the patch header
  patch-id: rewrite code that detects the beginning of a patch
  patch-id: make get_one_patchid() more extensible
  patch-id: call flush_current_id() only when needed
  t4204: patch-id supports various input format