[PATCH v3 1/2] t: add a test helper for getting hostname

[Ignacio Encinas <ignacio@iencinas.com>]

Avoid relying on whether the system running the test has "hostname"
installed or not, and expose the output of xgethostname through
test-tool.

Signed-off-by: Ignacio Encinas <ignacio@iencinas.com>
---
 Makefile                     |  1 +
 t/helper/test-tool.c         |  1 +
 t/helper/test-tool.h         |  1 +
 t/helper/test-xgethostname.c | 12 ++++++++++++
 t/t6500-gc.sh                |  3 +--
 5 files changed, 16 insertions(+), 2 deletions(-)
 create mode 100644 t/helper/test-xgethostname.c

diff --git a/Makefile b/Makefile
index 4e255c81f223..561d7a1fa268 100644
--- a/Makefile
+++ b/Makefile
@@ -863,6 +863,7 @@ TEST_BUILTINS_OBJS += test-userdiff.o
 TEST_BUILTINS_OBJS += test-wildmatch.o
 TEST_BUILTINS_OBJS += test-windows-named-pipe.o
 TEST_BUILTINS_OBJS += test-write-cache.o
+TEST_BUILTINS_OBJS += test-xgethostname.o
 TEST_BUILTINS_OBJS += test-xml-encode.o
 
 # Do not add more tests here unless they have extra dependencies. Add
diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c
index 482a1e58a4b6..9318900a2981 100644
--- a/t/helper/test-tool.c
+++ b/t/helper/test-tool.c
@@ -86,6 +86,7 @@ static struct test_cmd cmds[] = {
 	{ "truncate", cmd__truncate },
 	{ "userdiff", cmd__userdiff },
 	{ "urlmatch-normalization", cmd__urlmatch_normalization },
+	{ "xgethostname", cmd__xgethostname },
 	{ "xml-encode", cmd__xml_encode },
 	{ "wildmatch", cmd__wildmatch },
 #ifdef GIT_WINDOWS_NATIVE
diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h
index b1be7cfcf593..075d34bd3c0a 100644
--- a/t/helper/test-tool.h
+++ b/t/helper/test-tool.h
@@ -79,6 +79,7 @@ int cmd__trace2(int argc, const char **argv);
 int cmd__truncate(int argc, const char **argv);
 int cmd__userdiff(int argc, const char **argv);
 int cmd__urlmatch_normalization(int argc, const char **argv);
+int cmd__xgethostname(int argc, const char **argv);
 int cmd__xml_encode(int argc, const char **argv);
 int cmd__wildmatch(int argc, const char **argv);
 #ifdef GIT_WINDOWS_NATIVE
diff --git a/t/helper/test-xgethostname.c b/t/helper/test-xgethostname.c
new file mode 100644
index 000000000000..285746aef54a
--- /dev/null
+++ b/t/helper/test-xgethostname.c
@@ -0,0 +1,12 @@
+#include "test-tool.h"
+
+int cmd__xgethostname(int argc, const char **argv)
+{
+	char hostname[HOST_NAME_MAX + 1];
+
+	if (xgethostname(hostname, sizeof(hostname)))
+		die("unable to get the host name");
+
+	puts(hostname);
+	return 0;
+}
diff --git a/t/t6500-gc.sh b/t/t6500-gc.sh
index 18fe1c25e6a0..613c766e2bb4 100755
--- a/t/t6500-gc.sh
+++ b/t/t6500-gc.sh
@@ -395,7 +395,6 @@ test_expect_success 'background auto gc respects lock for all operations' '
 
 	# now fake a concurrent gc that holds the lock; we can use our
 	# shell pid so that it looks valid.
-	hostname=$(hostname || echo unknown) &&
 	shell_pid=$$ &&
 	if test_have_prereq MINGW && test -f /proc/$shell_pid/winpid
 	then
@@ -404,7 +403,7 @@ test_expect_success 'background auto gc respects lock for all operations' '
 		# the Windows PID in this case.
 		shell_pid=$(cat /proc/$shell_pid/winpid)
 	fi &&
-	printf "%d %s" "$shell_pid" "$hostname" >.git/gc.pid &&
+	printf "%d %s" "$shell_pid" "$(test-tool xgethostname)" >.git/gc.pid &&
 
 	# our gc should exit zero without doing anything
 	run_and_wait_for_auto_gc &&
-- 
2.44.0