submodule update: continue when a checkout fails

"git submodule update" stops at the first error and gives control
back to the user. Only after the user fixes the problematic
submodule and runs "git submodule update" again, the second error
is found. And the user needs to repeat until all the problems are
found and fixed one by one. This is tedious.

Instead, the command can remember which submodules it had trouble with,
continue updating the ones it can, and report which ones had errors at
the end. The user can run "git submodule update", find all the ones that
need minor fixing (e.g. working tree was dirty) to fix them in a single
pass. Then another "git submodule update" can be run to update all.

Note that the problematic submodules are skipped only when they are to
be integrated with a safer value of submodule.<name>.update option,
namely "checkout". Fixing a failure in a submodule that uses "rebase" or
"merge" may need an involved conflict resolution by the user, and
leaving too many submodules in states that need resolution would not
reduce the mental burden on the user.

Signed-off-by: Fredrik Gustafsson <iveqy@iveqy.com>
Mentored-by: Jens Lehmann <Jens.Lehmann@web.de>
Mentored-by: Heiko Voigt <hvoigt@hvoigt.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

2 files changed, 188 insertions, 6 deletions

diff --git a/git-submodule.sh b/git-submodule.sh
index d189a24c71..eb5eebcd96 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -444,7 +444,8 @@ cmd_update()
 	fi
 
 	cloned_modules=
-	module_list "$@" |
+	module_list "$@" | {
+	err=
 	while read mode sha1 stage path
 	do
 		if test "$stage" = U
@@ -525,17 +526,54 @@ cmd_update()
 				;;
 			esac
 
-			(clear_local_git_env; cd "$path" && $command "$sha1") ||
-			die "Unable to $action '$sha1' in submodule path '$path'"
-			say "Submodule path '$path': $msg '$sha1'"
+			if (clear_local_git_env; cd "$path" && $command "$sha1")
+			then
+				say "Submodule path '$path': $msg '$sha1'"
+			else
+				case $action in
+				rebase|merge)
+					die_with_status 2 "Unable to $action '$sha1' in submodule path '$path'"
+					;;
+				*)
+					err="${err};Failed to $action in submodule path '$path'"
+					continue
+					;;
+				esac
+			fi
 		fi
 
 		if test -n "$recursive"
 		then
-			(clear_local_git_env; cd "$path" && eval cmd_update "$orig_flags") ||
-			die "Failed to recurse into submodule path '$path'"
+			(clear_local_git_env; cd "$path" && eval cmd_update "$orig_flags")
+			res=$?
+			if test $res -gt 0
+			then
+				if test $res -eq 1
+				then
+					err="${err};Failed to recurse into submodule path '$path'"
+					continue
+				else
+					die_with_status $res "Failed to recurse into submodule path '$path'"
+				fi
+			fi
 		fi
 	done
+
+	if test -n "$err"
+	then
+		OIFS=$IFS
+		IFS=';'
+		for e in $err
+		do
+			if test -n "$e"
+			then
+				echo >&2 "$e"
+			fi
+		done
+		IFS=$OIFS
+		exit 1
+	fi
+	}
 }
 
 set_name_rev () {
diff --git a/t/t7406-submodule-update.sh b/t/t7406-submodule-update.sh
index 4f16fcce2b..807f761147 100755
--- a/t/t7406-submodule-update.sh
+++ b/t/t7406-submodule-update.sh
@@ -298,4 +298,148 @@ test_expect_success 'submodule update ignores update=rebase config for new submo
 	)
 '
 
+test_expect_success 'submodule update continues after checkout error' '
+	(cd super &&
+	 git reset --hard HEAD &&
+	 git submodule add ../submodule submodule2 &&
+	 git submodule init &&
+	 git commit -am "new_submodule" &&
+	 (cd submodule2 &&
+	  git rev-parse --max-count=1 HEAD > ../expect
+	 ) &&
+	 (cd submodule &&
+	  test_commit "update_submodule" file
+	 ) &&
+	 (cd submodule2 &&
+	  test_commit "update_submodule2" file
+	 ) &&
+	 git add submodule &&
+	 git add submodule2 &&
+	 git commit -m "two_new_submodule_commits" &&
+	 (cd submodule &&
+	  echo "" > file
+	 ) &&
+	 git checkout HEAD^ &&
+	 test_must_fail git submodule update &&
+	 (cd submodule2 &&
+	  git rev-parse --max-count=1 HEAD > ../actual
+	 ) &&
+	 test_cmp expect actual
+	)
+'
+test_expect_success 'submodule update continues after recursive checkout error' '
+	(cd super &&
+	 git reset --hard HEAD &&
+	 git checkout master &&
+	 git submodule update &&
+	 (cd submodule &&
+	  git submodule add ../submodule subsubmodule &&
+	  git submodule init &&
+	  git commit -m "new_subsubmodule"
+	 ) &&
+	 git add submodule &&
+	 git commit -m "update_submodule" &&
+	 (cd submodule &&
+	  (cd subsubmodule &&
+	   test_commit "update_subsubmodule" file
+	  ) &&
+	  git add subsubmodule &&
+	  test_commit "update_submodule_again" file &&
+	  (cd subsubmodule &&
+	   test_commit "update_subsubmodule_again" file
+	  ) &&
+	  test_commit "update_submodule_again_again" file
+	 ) &&
+	 (cd submodule2 &&
+	  git rev-parse --max-count=1 HEAD > ../expect &&
+	  test_commit "update_submodule2_again" file
+	 ) &&
+	 git add submodule &&
+	 git add submodule2 &&
+	 git commit -m "new_commits" &&
+	 git checkout HEAD^ &&
+	 (cd submodule &&
+	  git checkout HEAD^ &&
+	  (cd subsubmodule &&
+	   echo "" > file
+	  )
+	 ) &&
+	 test_must_fail git submodule update --recursive &&
+	 (cd submodule2 &&
+	  git rev-parse --max-count=1 HEAD > ../actual
+	 ) &&
+	 test_cmp expect actual
+	)
+'
+
+test_expect_success 'submodule update exit immediately in case of merge conflict' '
+	(cd super &&
+	 git checkout master &&
+	 git reset --hard HEAD &&
+	 (cd submodule &&
+	  (cd subsubmodule &&
+	   git reset --hard HEAD
+	  )
+	 ) &&
+	 git submodule update --recursive &&
+	 (cd submodule &&
+	  test_commit "update_submodule_2" file
+	 ) &&
+	 (cd submodule2 &&
+	  test_commit "update_submodule2_2" file
+	 ) &&
+	 git add submodule &&
+	 git add submodule2 &&
+	 git commit -m "two_new_submodule_commits" &&
+	 (cd submodule &&
+	  git checkout master &&
+	  test_commit "conflict" file &&
+	  echo "conflict" > file
+	 ) &&
+	 git checkout HEAD^ &&
+	 (cd submodule2 &&
+	  git rev-parse --max-count=1 HEAD > ../expect
+	 ) &&
+	 git config submodule.submodule.update merge &&
+	 test_must_fail git submodule update &&
+	 (cd submodule2 &&
+	  git rev-parse --max-count=1 HEAD > ../actual
+	 ) &&
+	 test_cmp expect actual
+	)
+'
+test_expect_success 'submodule update exit immediately after recursive rebase error' '
+	(cd super &&
+	 git checkout master &&
+	 git reset --hard HEAD &&
+	 (cd submodule &&
+	  git reset --hard HEAD &&
+	  git submodule update --recursive
+	 ) &&
+	 (cd submodule &&
+	  test_commit "update_submodule_3" file
+	 ) &&
+	 (cd submodule2 &&
+	  test_commit "update_submodule2_3" file
+	 ) &&
+	 git add submodule &&
+	 git add submodule2 &&
+	 git commit -m "two_new_submodule_commits" &&
+	 (cd submodule &&
+	  git checkout master &&
+	  test_commit "conflict2" file &&
+	  echo "conflict" > file
+	 ) &&
+	 git checkout HEAD^ &&
+	 (cd submodule2 &&
+	  git rev-parse --max-count=1 HEAD > ../expect
+	 ) &&
+	 git config submodule.submodule.update rebase &&
+	 test_must_fail git submodule update &&
+	 (cd submodule2 &&
+	  git rev-parse --max-count=1 HEAD > ../actual
+	 ) &&
+	 test_cmp expect actual
+	)
+'
 test_done