Work around t5799 failure with curl v8.16.0 (#801)

I investigated a couple of new test failures over in #799; Essentially,
t5799.13(curl-connect: no server) no longer received the expected
`CURLE_COULDNT_CONNECT` immediately, but instead received
`CURLE_OPERATION_TIMEDOUT` after 5 minutes (!), and due to
internal details that problem was repeated 4 times (!!!).

Turns out that the regression was _not_ introduced by the patches in
that PR, but by the independent Git for Windows SDK update of cURL
to v8.16.0.

I integrated a fix into the Git for Windows SDK in
git-for-windows/MINGW-packages#163, but
since Microsoft Git also targets Linux and macOS (where we do not
control the cURL version), here is a work-around.

This PR also adds some clean-ups for the `t5799-gvfs-helper.sh` test
script in general, e.g. to improve future debug'ability.

Author: dscho

gvfs-helper.c

@@ -254,6 +254,7 @@
 #include "wrapper.h"
 #include "packfile.h"
 #include "date.h"
+#include "versioncmp.h"
 
 #define TR2_CAT "gvfs-helper"
 
@@ -286,6 +287,11 @@ static const char *const server_usage[] = {
 	NULL
 };
 
+static const char *const curl_version_usage[] = {
+	N_("git gvfs-helper [<main_options>] curl-version [<operator> <version>]"),
+	NULL
+};
+
 /*
  * "commitDepth" field in gvfs protocol
  */
@@ -375,6 +381,7 @@ static struct gh__global {
 	int cache_server_is_initialized; /* did sub-command look for one */
 	int main_creds_need_approval; /* try to only approve them once */
 
+	unsigned long connect_timeout_ms;
 } gh__global;
 
 enum gh__server_type {
@@ -2964,6 +2971,10 @@ static void do_req(const char *url_base,
 		curl_easy_setopt(slot->curl, CURLOPT_NOPROGRESS, 1L);
 	}
 
+	if (gh__global.connect_timeout_ms)
+		curl_easy_setopt(slot->curl, CURLOPT_CONNECTTIMEOUT_MS,
+				gh__global.connect_timeout_ms);
+
 	gh__run_one_slot(slot, params, status);
 	strbuf_release(&rest_url);
 }
@@ -3672,6 +3683,9 @@ static enum gh__error_code do_sub_cmd__get(int argc, const char **argv)
 	static struct option get_options[] = {
 		OPT_INTEGER('r', "max-retries", &gh__cmd_opts.max_retries,
 			    N_("retries for transient network errors")),
+		OPT_UNSIGNED(0, "connect-timeout-ms",
+			     &gh__global.connect_timeout_ms,
+			     N_("try to connect only for this many milliseconds")),
 		OPT_END(),
 	};
 
@@ -4148,6 +4162,37 @@ static enum gh__error_code do_sub_cmd__server(int argc, const char **argv)
 	return ec;
 }
 
+static enum gh__error_code do_sub_cmd__curl_version(int argc, const char **argv)
+{
+	static struct option curl_version_options[] = {
+		OPT_END(),
+	};
+	const char *current_version = curl_version_info(CURLVERSION_NOW)->version;
+
+	trace2_cmd_mode("curl-version");
+
+	if (argc > 1 && !strcmp(argv[1], "-h"))
+		usage_with_options(curl_version_usage, curl_version_options);
+
+	argc = parse_options(argc, argv, NULL,
+			     curl_version_options, curl_version_usage, 0);
+
+	if (argc == 0)
+		printf("%s\n", current_version);
+	else if (argc != 2)
+		die("expected [<operator> <version>], but got %d parameters", argc);
+	else {
+		int cmp = versioncmp(current_version, argv[1]);
+
+		return (strchr(argv[0], '=') && !cmp) ||
+			(strchr(argv[0], '>') && cmp > 0) ||
+			(strchr(argv[0], '<') && cmp < 0) ?
+			GH__ERROR_CODE__OK : GH__ERROR_CODE__ERROR;
+	}
+
+	return GH__ERROR_CODE__OK;
+}
+
 static enum gh__error_code do_sub_cmd(int argc, const char **argv)
 {
 	if (!strcmp(argv[0], "get"))
@@ -4172,6 +4217,9 @@ static enum gh__error_code do_sub_cmd(int argc, const char **argv)
 	if (!strcmp(argv[0], "server"))
 		return do_sub_cmd__server(argc, argv);
 
+	if (!strcmp(argv[0], "curl-version"))
+		return do_sub_cmd__curl_version(argc, argv);
+
 	return GH__ERROR_CODE__USAGE;
 }
 

t/t5799-gvfs-helper.sh

@@ -368,7 +368,7 @@ verify_objects_in_shared_cache () {
 	# See if any of the objects are missing from repo_t1.
 	#
 	git -C "$REPO_T1" cat-file --batch-check <"$1" >OUT.bc_actual || return 1
-	grep -q " missing" OUT.bc_actual && return 1
+	test_grep " missing" OUT.bc_actual && return 1
 	#
 	# See if any of the objects have different sizes or types than repo_src.
 	#
@@ -540,7 +540,7 @@ test_expect_success 'basic: GET gvfs/config' '
 	# The cache-server URL should be listed in the gvfs/config output.
 	# We confirm this before assuming error-mode will work.
 	#
-	grep -q "$CACHE_URL" OUT.output
+	test_grep "$CACHE_URL" OUT.output
 '
 
 test_expect_success 'basic: GET cache-server multi-get error-mode' '
@@ -799,14 +799,14 @@ test_expect_success 'basic: PREFETCH up-to-date' '
 #################################################################
 
 mayhem_observed__close__connections () {
-	if $(grep -q "transient" OUT.stderr)
+	if grep "transient" OUT.stderr
 	then
 		# Transient errors should retry.
 		# 1 for initial request + 2 retries.
 		#
 		verify_connection_count 3
 		return $?
-	elif $(grep -q "hard_fail" OUT.stderr)
+	elif grep "hard_fail" OUT.stderr
 	then
 		# Hard errors should not retry.
 		#
@@ -837,10 +837,10 @@ mayhem_observed__close () {
 	# going to verify the connection counts based upon what type of error
 	# gvfs-helper claimed it to be.
 	#
-	if      $(grep -q "error: get: (curl:18)" OUT.stderr) ||
-		$(grep -q "error: get: (curl:52)" OUT.stderr) ||
-		$(grep -q "error: get: (curl:55)" OUT.stderr) ||
-		$(grep -q "error: get: (curl:56)" OUT.stderr)
+	if      grep "error: get: (curl:18)" OUT.stderr ||
+		grep "error: get: (curl:52)" OUT.stderr ||
+		grep "error: get: (curl:55)" OUT.stderr ||
+		grep "error: get: (curl:56)" OUT.stderr
 	then
 		mayhem_observed__close__connections
 		return $?
@@ -850,9 +850,25 @@ mayhem_observed__close () {
 	fi
 }
 
+test_lazy_prereq CURL_8_16_0 '
+	git gvfs-helper curl-version = 8.16.0 ||
+	test 8.15.0-DEV = "$(git gvfs-helper curl-version)"
+'
+
 test_expect_success 'curl-error: no server' '
 	test_when_finished "per_test_cleanup" &&
 
+	connect_timeout_ms= &&
+	# CURLE_COULDNT_CONNECT 7
+	regex="error: get: (curl:7)" &&
+	if test_have_prereq CURL_8_16_0
+	then
+		connect_timeout_ms=--connect-timeout-ms=200 &&
+		# CURLE_COULDNT_CONNECT 7
+		# CURLE_OPERATION_TIMEDOUT 28
+		regex="error: get: (curl:\(7\|28\))"
+	fi &&
+
 	# Try to do a multi-get without a server.
 	#
 	# Use small max-retry value because of exponential backoff,
@@ -864,10 +880,9 @@ test_expect_success 'curl-error: no server' '
 		--remote=origin \
 		get \
 		--max-retries=2 \
+		$connect_timeout_ms \
 		<"$OIDS_FILE" >OUT.output 2>OUT.stderr &&
-
-	# CURLE_COULDNT_CONNECT 7
-	grep -q "error: get: (curl:7)" OUT.stderr
+	test_grep "$regex" OUT.stderr
 '
 
 test_expect_success 'curl-error: close socket while reading request' '
@@ -980,7 +995,7 @@ test_expect_success 'http-error: 503 Service Unavailable (with retry)' '
 
 	stop_gvfs_protocol_server &&
 
-	grep -q "error: get: (http:503)" OUT.stderr &&
+	test_grep "error: get: (http:503)" OUT.stderr &&
 	verify_connection_count 3
 '
 
@@ -998,7 +1013,7 @@ test_expect_success 'http-error: 429 Service Unavailable (with retry)' '
 
 	stop_gvfs_protocol_server &&
 
-	grep -q "error: get: (http:429)" OUT.stderr &&
+	test_grep "error: get: (http:429)" OUT.stderr &&
 	verify_connection_count 3
 '
 
@@ -1016,7 +1031,7 @@ test_expect_success 'http-error: 404 Not Found (no retry)' '
 
 	stop_gvfs_protocol_server &&
 
-	grep -q "error: get: (http:404)" OUT.stderr &&
+	test_grep "error: get: (http:404)" OUT.stderr &&
 	verify_connection_count 1
 '
 
@@ -1082,7 +1097,7 @@ test_expect_success 'http-error: 503 Service Unavailable (with retry and fallbac
 
 	stop_gvfs_protocol_server &&
 
-	grep -q "error: get: (http:503)" OUT.stderr &&
+	test_grep "error: get: (http:503)" OUT.stderr &&
 	verify_connection_count 6
 '
 
@@ -1113,7 +1128,7 @@ test_expect_success 'http-error: 503 Service Unavailable (with retry and no-fall
 
 	stop_gvfs_protocol_server &&
 
-	grep -q "error: get: (http:503)" OUT.stderr &&
+	test_grep "error: get: (http:503)" OUT.stderr &&
 	verify_connection_count 3
 '
 
@@ -1123,10 +1138,7 @@ test_expect_success 'http-error: 503 Service Unavailable (with retry and no-fall
 #################################################################
 
 test_lazy_prereq CURL_7_75_OR_NEWER '
-	case "$(curl version | sed -n "1s/^curl \([^ ]*\).*/\1/p")" in
-	""|[0-6].*|7.[0-9]*.*|7.[1-6][0-9].*|7.7[0-4]*.*) return 1;;
-	*) return 0;;
-	esac
+	git gvfs-helper curl-version ">=" 7.75.0
 '
 
 test_expect_success 'HTTP GET Auth on Origin Server' '
@@ -1534,7 +1546,7 @@ test_expect_success 'prefetch corrupt pack without idx' '
 	# Verify corruption detected in pack when building
 	# local idx file for it.
 
-	grep -q "error: .* index-pack failed" <OUT.stderr
+	test_grep "error: .* index-pack failed" OUT.stderr
 '
 
 # Send corrupt PACK files with IDX files.  Since the cache server