git-debrebase(5): Add ILLEGAL OPERATIONS section.

Re #905004.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/debian/changelog b/debian/changelog
index 3948db718a9501aa3ba5fda44aae2ff6d5eac9f8..6f5e15575e60df1deade92d3fa8085483b9ef26e 100644 (file)
--- a/debian/changelog
+++ b/debian/changelog
@@ -11,6 +11,7 @@ dgit (6.3~) unstable; urgency=medium
   * git-debrebase: Improve error messages for bad options.
   * git-debrebase: Improve error message for convert-from-gbp
     upstream discrepancy.  Closes:#905078.
+  * git-debrebase(5): Add ILLEGAL OPERATIONS section.  (Re#905004.)
 
  --
 

diff --git a/git-debrebase.5.pod b/git-debrebase.5.pod
index 52fb60b952d331c7632ab3abc2c8b424f80de624..d39ad9484986fb022e98e735a030d91f6e136063 100644 (file)
--- a/git-debrebase.5.pod
+++ b/git-debrebase.5.pod
@@ -487,6 +487,48 @@ These patch files can be stripped out and/or regenerated as needed.
 
 =back
 
+=head1 ILLEGAL OPERATIONS
+
+Some git operations are not permitted in this data model.
+Performing them will break git-debrebase.
+
+=over
+
+=item General merges
+
+See L</OTHER MERGES>, above.
+
+=item git-rebase starting too soon, or without base argument
+
+git-rebase must not be invoked in such a way that
+the chosen base is before the anchor,
+or before the last pseudomerge.
+This is because git-rebase mangles merges.
+git rebase --preserve-merges is also dangerous.
+
+git-rebase without a base argument will often start too early.
+
+For these reasons,
+it is better to use git-debrebase and
+let it choose the base
+for your rebase.
+If you do realise you have make this mistake,
+it is best to use the reflog to recover to a suitable
+good previous state.
+
+=item Editing debian/patches
+
+debian/patches is an output from git-debrebase,
+not an input.
+If you edit patches git-debrebase will complain
+and refuse to work.
+If you add patches your work is likely to be discarded.
+
+Instead of editing patches,
+use git-debrebase to edit the corresponding commits.
+
+=back
+
 =head1 COMMIT MESSAGE ANNOTATIONS
 
 git-debrebase makes annotations