4 files changed, 65 insertions, 0 deletions
diff --git a/t/helper/meson.build b/t/helper/meson.build
index d4e8b26df8..675e64c010 100644
--- a/t/helper/meson.build
+++ b/t/helper/meson.build
@@ -77,6 +77,7 @@ test_tool_sources = [
   'test-windows-named-pipe.c',
   'test-write-cache.c',
   'test-xml-encode.c',
+  'test-zlib.c',
 ]
 
 test_tool = executable('test-tool',
diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c
index 74812ed86d..a7abc618b3 100644
--- a/t/helper/test-tool.c
+++ b/t/helper/test-tool.c
@@ -91,6 +91,7 @@ static struct test_cmd cmds[] = {
 	{ "windows-named-pipe", cmd__windows_named_pipe },
 #endif
 	{ "write-cache", cmd__write_cache },
+	{ "zlib", cmd__zlib },
 };
 
 static NORETURN void die_usage(void)
diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h
index 2571a3ccfe..7f150fa1eb 100644
--- a/t/helper/test-tool.h
+++ b/t/helper/test-tool.h
@@ -84,6 +84,7 @@ int cmd__wildmatch(int argc, const char **argv);
 int cmd__windows_named_pipe(int argc, const char **argv);
 #endif
 int cmd__write_cache(int argc, const char **argv);
+int cmd__zlib(int argc, const char **argv);
 
 int cmd_hash_impl(int ac, const char **av, int algo, int unsafe);
 
diff --git a/t/helper/test-zlib.c b/t/helper/test-zlib.c
new file mode 100644
index 0000000000..de7e9edee1
--- /dev/null
+++ b/t/helper/test-zlib.c
@@ -0,0 +1,62 @@
+#include "test-tool.h"
+#include "git-zlib.h"
+#include "strbuf.h"
+
+static const char *zlib_usage = "test-tool zlib [inflate|deflate]";
+
+static void do_zlib(struct git_zstream *stream,
+		    int (*zlib_func)(git_zstream *, int),
+		    int fd_in, int fd_out)
+{
+	struct strbuf buf_in = STRBUF_INIT;
+	int status = Z_OK;
+
+	if (strbuf_read(&buf_in, fd_in, 0) < 0)
+		die_errno("read error");
+
+	stream->next_in = (unsigned char *)buf_in.buf;
+	stream->avail_in = buf_in.len;
+
+	while (status == Z_OK ||
+	       (status == Z_BUF_ERROR && !stream->avail_out)) {
+		unsigned char buf_out[4096];
+
+		stream->next_out = buf_out;
+		stream->avail_out = sizeof(buf_out);
+
+		status = zlib_func(stream, Z_FINISH);
+		if (write_in_full(fd_out, buf_out,
+				  sizeof(buf_out) - stream->avail_out) < 0)
+			die_errno("write error");
+	}
+
+	if (status != Z_STREAM_END)
+		die("zlib error %d", status);
+
+	strbuf_release(&buf_in);
+}
+
+int cmd__zlib(int argc, const char **argv)
+{
+	git_zstream stream;
+
+	if (argc != 2)
+		usage(zlib_usage);
+
+	memset(&stream, 0, sizeof(stream));
+
+	if (!strcmp(argv[1], "inflate")) {
+		git_inflate_init(&stream);
+		do_zlib(&stream, git_inflate, 0, 1);
+		git_inflate_end(&stream);
+	} else if (!strcmp(argv[1], "deflate")) {
+		git_deflate_init(&stream, Z_DEFAULT_COMPRESSION);
+		do_zlib(&stream, git_deflate, 0, 1);
+		git_deflate_end(&stream);
+	} else {
+		error("unknown mode: %s", argv[1]);
+		usage(zlib_usage);
+	}
+
+	return 0;
+}