commit baaae61518bf323d22055a3b02fc9e129ee6d567
from: Stefan Sperling <stsp@stsp.name>
date: Wed Jun 07 06:55:56 2023 UTC

make gotd avoid a "failed to push some refs" error from no-op 'git push'

gotsh was sending errors such as "unexpected end of file" and
"unexpected flush-pkt" to the client when the client disconnected
immediately after receiving reference announcements from the server.

As a result, 'git push' with both sides up-to-date would show an
obscure error message:

 = [up to date]      main -> main
 error: failed to push some refs to 'ssh://example.com/git/repo.git

Now we see:

 = [up to date]      main -> main
 Everything up-to-date

ok jamsek

commit - cf31b4749a965b44fa03a3c98bdfc8b60f2c987d
commit + baaae61518bf323d22055a3b02fc9e129ee6d567
blob - 8f00f2699c2d87d84a815df4188c27ed9fcc45c0
blob + e4c9601581a5f7e5f5944692c0f36c0130bacfdd
--- gotd/session.c
+++ gotd/session.c
@@ -1046,6 +1046,17 @@ session_dispatch_client(int fd, short events, void *ar
 		if (err) {
 			if (err->code == GOT_ERR_PRIVSEP_READ)
 				err = NULL;
+			else if (err->code == GOT_ERR_EOF &&
+			    client->state == GOTD_STATE_EXPECT_CAPABILITIES) {
+				/*
+				 * The client has closed its socket before
+				 * sending its capability announcement.
+				 * This can happen when Git clients have
+				 * no ref-updates to send.
+				 */
+				disconnect_on_error(client, err);
+				return;
+			}
 			break;
 		}
 
blob - 3d1c9a901f008fc32a17f1ab6a9abc5b444cf986
blob + b811009e08d9088194ccc086a17fcecac0da7fde
--- lib/serve.c
+++ lib/serve.c
@@ -1270,7 +1270,10 @@ serve_write(int infd, int outfd, int gotd_sock, const 
 		if (err)
 			goto done;
 		if (n == 0) {
-			if (curstate != STATE_EXPECT_MORE_REF_UPDATES) {
+			if (curstate == STATE_EXPECT_REF_UPDATE) {
+				/* The client will not send us anything. */
+				goto done;
+			} else if (curstate != STATE_EXPECT_MORE_REF_UPDATES) {
 				err = got_error_msg(GOT_ERR_BAD_PACKET,
 				    "unexpected flush packet received");
 				goto done;
blob - daff924b47ca360160665215790f700bf0f8bfda
blob + 4ae6fbc520b21e761719a82232e309e8e3747239
--- regress/gotd/repo_write.sh
+++ regress/gotd/repo_write.sh
@@ -108,6 +108,16 @@ EOF
 	ret=$?
 	if [ $ret -ne 0 ]; then
 		echo "git pull failed unexpectedly" >&2
+		test_done "$testroot" "1"
+		return 1
+	fi
+
+	# Verify that git push reports no changes to send and no error.
+	(cd $testroot/repo-clone3 && git push -q > $testroot/stdout \
+		2> $testroot/stderr)
+	ret=$?
+	if [ $ret -ne 0 ]; then
+		echo "git push failed unexpectedly" >&2
 		test_done "$testroot" "1"
 		return 1
 	fi