t6022: New tests checking for unnecessary updates of files

diff --git a/git-am.sh b/git-am.sh
index e7f008c7baae2ff484e16882e199b6b9d75195aa..6cdd5910db50c96df3d149fba172750cb10c09cb 100755 (executable)
--- a/git-am.sh
+++ b/git-am.sh
@@ -5,7 +5,7 @@
 SUBDIRECTORY_OK=Yes
 OPTIONS_KEEPDASHDASH=
 OPTIONS_SPEC="\
-git am [options] [<mbox>|<Maildir>...]
+git am [options] [(<mbox>|<Maildir>)...]
 git am [options] (--resolved | --skip | --abort)
 --
 i,interactive   run interactively
@@ -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"
@@ -137,7 +159,7 @@ It does not apply to blobs recorded in its index."
     export GITHEAD_$his_tree
     if test -n "$GIT_QUIET"
     then
-           export GIT_MERGE_VERBOSITY=0
+           GIT_MERGE_VERBOSITY=0 && export GIT_MERGE_VERBOSITY
     fi
     git-merge-recursive $orig_tree -- HEAD $his_tree || {
            git rerere $allow_rerere_autoupdate
@@ -419,10 +441,11 @@ then
                        exec git rebase --abort
                fi
                git rerere clear
-               test -f "$dotest/dirtyindex" || {
+               if safe_to_abort
+               then
                        git read-tree --reset -u HEAD ORIG_HEAD
                        git reset ORIG_HEAD
-               }
+               fi
                rm -fr "$dotest"
                exit ;;
        esac
@@ -444,12 +467,12 @@ else
                                set x
                                first=
                        }
-                       case "$arg" in
-                       /*)
-                               set "$@" "$arg" ;;
-                       *)
-                               set "$@" "$prefix$arg" ;;
-                       esac
+                       if is_absolute_path "$arg"
+                       then
+                               set "$@" "$arg"
+                       else
+                               set "$@" "$prefix$arg"
+                       fi
                done
                shift
        fi
@@ -554,13 +577,6 @@ then
        resume=
 fi
 
-if test "$this" -gt "$last"
-then
-       say Nothing to do.
-       rm -fr "$dotest"
-       exit
-fi
-
 while test "$this" -le "$last"
 do
        msgnum=`printf "%0${prec}d" $this`