On Sun, Jun 04, 2023 at 06:16:12PM +0200, Omar Polo wrote:
> forgot to attach a patch? :-)

Oops, here it is!

-- 
James


diff 427615296bc79cda685540d7fc241444b7447980 refs/heads/falsifian/mg_noclobber
commit - 427615296bc79cda685540d7fc241444b7447980
commit + 23e47420c8285db353b4e009c38fc1801d6a534c
blob - f4666b0aa2b87365b32db745d93c6feae807d6a4
blob + d853c6a2eec0e5067f684d2bdf43979a898c26bb
--- got/got.c
+++ got/got.c
@@ -13268,7 +13268,21 @@ cmd_merge(int argc, char *argv[])
 	if (error)
 		goto done;
 
+	error = got_ref_open(&wt_branch, repo,
+	    got_worktree_get_head_ref_name(worktree), 0);
+	if (error)
+		goto done;
+	error = got_ref_resolve(&wt_branch_tip, repo, wt_branch);
+	if (error)
+		goto done;
+
 	if (continue_merge) {
+		struct got_object_id *base_commit_id;
+		base_commit_id = got_worktree_get_base_commit_id(worktree);
+		if (got_object_id_cmp(wt_branch_tip, base_commit_id) != 0) {
+			error = got_error(GOT_ERR_MERGE_COMMIT_OUT_OF_DATE);
+			goto done;
+		}
 		error = got_worktree_merge_continue(&branch_name,
 		    &branch_tip, &fileindex, worktree, repo);
 		if (error)
@@ -13287,13 +13301,6 @@ cmd_merge(int argc, char *argv[])
 			goto done;
 	}
 
-	error = got_ref_open(&wt_branch, repo,
-	    got_worktree_get_head_ref_name(worktree), 0);
-	if (error)
-		goto done;
-	error = got_ref_resolve(&wt_branch_tip, repo, wt_branch);
-	if (error)
-		goto done;
 	error = got_commit_graph_find_youngest_common_ancestor(&yca_id,
 	    wt_branch_tip, branch_tip, 0, repo,
 	    check_cancelled, NULL);
blob - 3b047e438a7e4fff23c4e9f6c1ada623765a80dc
blob + 0582e35816efd0e75172f961b9d274e6c249d83d
--- include/got_error.h
+++ include/got_error.h
@@ -158,7 +158,6 @@
 #define GOT_ERR_NOT_MERGING	141
 #define GOT_ERR_MERGE_OUT_OF_DATE 142
 #define GOT_ERR_MERGE_STAGED_PATHS 143
-#define GOT_ERR_MERGE_COMMIT_OUT_OF_DATE 143
 #define GOT_ERR_MERGE_BUSY	144
 #define GOT_ERR_MERGE_PATH	145
 #define GOT_ERR_FILE_BINARY	146
@@ -185,6 +184,7 @@
 #define GOT_ERR_UID		167
 #define GOT_ERR_GID		168
 #define GOT_ERR_NO_PROG		169
+#define GOT_ERR_MERGE_COMMIT_OUT_OF_DATE 170
 
 struct got_error {
         int code;
blob - c3b2bdd9b1622256235092145718299216397766
blob + feebeac691a9e648011aa46d28905422aae9db1a
--- lib/error.c
+++ lib/error.c
@@ -203,9 +203,6 @@ static const struct got_error got_errors[] = {
 	{ GOT_ERR_MERGE_STAGED_PATHS, "work tree contains files with staged "
 	    "changes; these changes must be unstaged before merging can "
 	    "proceed" },
-	{ GOT_ERR_MERGE_COMMIT_OUT_OF_DATE, "merging cannot proceed because "
-	    "the work tree is no longer up-to-date; merge must be aborted "
-	    "and retried" },
 	{ GOT_ERR_MERGE_BUSY,"a merge operation is in progress in this "
 	    "work tree and must be continued or aborted first" },
 	{ GOT_ERR_MERGE_PATH,	"cannot merge branch which contains "
@@ -235,6 +232,9 @@ static const struct got_error got_errors[] = {
 	{ GOT_ERR_UID, "bad user ID" },
 	{ GOT_ERR_GID, "bad group ID" },
 	{ GOT_ERR_NO_PROG, "command not found or not accessible" },
+	{ GOT_ERR_MERGE_COMMIT_OUT_OF_DATE, "merging cannot proceed because "
+	    "the work tree is no longer up-to-date; merge must be aborted "
+	    "and retried" },
 };
 
 static struct got_custom_error {
blob - 9d45bcc89fba03349491b41c260b4fc0c9606531
blob + e97f10e73cd0df0521ce4e36b40897121837e8d5
--- lib/worktree.c
+++ lib/worktree.c
@@ -8409,20 +8409,6 @@ got_worktree_merge_commit(struct got_object_id **new_c
 	if (err)
 		goto done;
 
-	TAILQ_FOREACH(pe, &commitable_paths, entry) {
-		struct got_commitable *ct = pe->data;
-		const char *ct_path = ct->in_repo_path;
-
-		while (ct_path[0] == '/')
-			ct_path++;
-		err = check_out_of_date(ct_path, ct->status,
-		    ct->staged_status, ct->base_blob_id, ct->base_commit_id,
-		    head_commit_id, repo, GOT_ERR_MERGE_COMMIT_OUT_OF_DATE);
-		if (err)
-			goto done;
-
-	}
-
 	mcm_arg.worktree = worktree;
 	mcm_arg.branch_name = branch_name;
 	err = commit_worktree(new_commit_id, &commitable_paths,
blob - df6f2f9edf54a23ff9b1e9f05267a77673a4fbcf
blob + ca27e157f924c0abac516cda4f26581c04e3cc21
--- regress/cmdline/merge.sh
+++ regress/cmdline/merge.sh
@@ -590,6 +590,67 @@ test_merge_abort() {
 	test_done "$testroot" "$ret"
 }
 
+test_merge_continue_new_commit() {
+	# "got merge -c" should refuse to run if the current branch tip has
+	# changed since the merge was started, to avoid clobbering the changes.
+	local testroot=`test_init merge_continue_new_commit`
+
+	(cd $testroot/repo && git checkout -q -b newbranch)
+	echo "modified delta on branch" > $testroot/repo/gamma/delta
+	git_commit $testroot/repo -m "committing to delta on newbranch"
+
+	(cd $testroot/repo && git checkout -q master)
+	echo "modified alpha on master" > $testroot/repo/alpha
+	git_commit $testroot/repo -m "committing to alpha on master"
+
+	got checkout -b master $testroot/repo $testroot/wt > /dev/null
+	ret=$?
+	if [ $ret -ne 0 ]; then
+		echo "got checkout failed unexpectedly" >&2
+		test_done "$testroot" "$ret"
+		return 1
+	fi
+
+	(cd $testroot/wt && got merge -n newbranch >/dev/null)
+	ret=$?
+	if [ $ret -ne 0 ]; then
+		echo "got merge failed unexpectedly" >&2
+		test_done "$testroot" "$ret"
+		return 1
+	fi
+
+	echo "modified alpha again on master" > $testroot/repo/alpha
+	git_commit $testroot/repo -m "committing to alpha on master again"
+
+	(cd $testroot/wt && got merge -c > $testroot/stdout 2> $testroot/stderr)
+	ret=$?
+	if [ $ret -eq 0 ]; then
+		echo "got merge succeeded unexpectedly" >&2
+		test_done "$testroot" "1"
+		return 1
+	fi
+
+	echo -n > $testroot/stdout.expected
+	cmp -s $testroot/stdout.expected $testroot/stdout
+	ret=$?
+	if [ $ret -ne 0 ]; then
+		diff -u $testroot/stdout.expected $testroot/stdout
+		test_done "$testroot" "$ret"
+		return 1
+	fi
+
+	echo -n "got: merging cannot proceed because the work tree is no " \
+		> $testroot/stderr.expected
+	echo "longer up-to-date; merge must be aborted and retried" \
+		>> $testroot/stderr.expected
+	cmp -s $testroot/stderr.expected $testroot/stderr
+	ret=$?
+	if [ $ret -ne 0 ]; then
+		diff -u $testroot/stderr.expected $testroot/stderr
+	fi
+	test_done "$testroot" "$ret"
+}
+
 test_merge_abort() {
 	local testroot=`test_init merge_abort`
 	local commit0=`git_show_head $testroot/repo`
@@ -1506,6 +1567,7 @@ run_test test_merge_abort
 test_parseargs "$@"
 run_test test_merge_basic
 run_test test_merge_continue
+run_test test_merge_continue_new_commit
 run_test test_merge_abort
 run_test test_merge_in_progress
 run_test test_merge_path_prefix