am --abort: keep unrelated commits since the last failure and warn

After making commits (either by pulling or doing their own work) after a
failed "am", the user will be reminded by next "am" invocation that there
was a failed "am" that the user needs to decide to resolve or to get rid
of the old "am" attempt.  The "am --abort" option was meant to help the
latter.  However, it rewinded the HEAD back to the beginning of the failed
"am" attempt, discarding commits made (perhaps by mistake) since.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-am.sh b/git-am.sh
index de116a29ef091a23f60603a28f1260ba60f054ac..e5671f61c61aad7fe47e174a31b534da6d8d2798 100755 (executable)
--- a/git-am.sh
+++ b/git-am.sh
@@ -68,9 +68,31 @@ sq () {
 
 stop_here () {
     echo "$1" >"$dotest/next"
+    git rev-parse --verify -q HEAD >"$dotest/abort-safety"
     exit 1
 }
 
+safe_to_abort () {
+       if test -f "$dotest/dirtyindex"
+       then
+               return 1
+       fi
+
+       if ! test -s "$dotest/abort-safety"
+       then
+               return 0
+       fi
+
+       abort_safety=$(cat "$dotest/abort-safety")
+       if test "z$(git rev-parse --verify -q HEAD)" = "z$abort_safety"
+       then
+               return 0
+       fi
+       echo >&2 "You seem to have moved HEAD since the last 'am' failure."
+       echo >&2 "Not rewinding to ORIG_HEAD"
+       return 1
+}
+
 stop_here_user_resolve () {
     if [ -n "$resolvemsg" ]; then
            printf '%s\n' "$resolvemsg"
@@ -419,10 +441,11 @@ then
                        exec git rebase --abort
                fi
                git rerere clear
-               test -f "$dotest/dirtyindex" || {
+               if safe_to_abort
+               then
                        git read-tree --reset -u HEAD ORIG_HEAD
                        git reset ORIG_HEAD
-               }
+               fi
                rm -fr "$dotest"
                exit ;;
        esac

diff --git a/t/t4151-am-abort.sh b/t/t4151-am-abort.sh
index b55c4117884744db8eda17e42fe05e0e65216215..c95c4ccc393d0863ad53b6a2a684893282d7d9e6 100755 (executable)
--- a/t/t4151-am-abort.sh
+++ b/t/t4151-am-abort.sh
@@ -62,4 +62,13 @@ do
 
 done
 
+test_expect_success 'am --abort will keep the local commits intact' '
+       test_must_fail git am 0004-*.patch &&
+       test_commit unrelated &&
+       git rev-parse HEAD >expect &&
+       git am --abort &&
+       git rev-parse HEAD >actual &&
+       test_cmp expect actual
+'
+
 test_done