--- a/tests/test-hook.t Thu Mar 23 19:10:15 2023 +0100
+++ b/tests/test-hook.t Thu Mar 23 11:24:47 2023 +0000
@@ -1430,3 +1430,42 @@
### no ######## plain: <unset>
### auto ###### plain: 1
Mercurial Distributed SCM (*) (glob)
+
+Test hook that change the underlying repo
+=========================================
+
+blackbox access the dirstate afterward and can see a changelog / dirstate
+desync.
+
+
+ $ cd $TESTTMP
+ $ cat <<EOF >> $HGRCPATH
+ > [extensions]
+ > blackbox=
+ > [hooks]
+ > post-merge = hg commit -m "auto merge"
+ > EOF
+
+ $ hg init t
+ $ cd t
+ $ touch ".hgignore"
+ $ hg commit -Am "initial" -d'0 0'
+ adding .hgignore
+
+ $ echo This is file a1 > a
+ $ hg commit -Am "commit #1" -d'0 0'
+ adding a
+
+ $ hg update 0
+ 0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+ $ echo This is file b1 > b
+ $ hg commit -Am "commit #2" -d'0 0'
+ adding b
+ created new head
+
+ $ hg merge 1
+ 1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+ (branch merge, don't forget to commit)
+ warning: ignoring unknown working parent 449f60fb3fe2! (known-bad-output !)
+
+ $ cd ..