[PATCH 3/5] trace-cmd: Use errno from zlib, if available

["Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>]

Some zlib APIs set the errno in case of an error and return Z_ERRNO.
In these cases, errno should not be overwritten by the tarce-cmd zlib
wrappers.

Suggested-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 lib/trace-cmd/trace-compress-zlib.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/trace-cmd/trace-compress-zlib.c b/lib/trace-cmd/trace-compress-zlib.c
index 41342597..0dfd4f15 100644
--- a/lib/trace-cmd/trace-compress-zlib.c
+++ b/lib/trace-cmd/trace-compress-zlib.c
@@ -33,6 +33,8 @@ static int zlib_compress(const void *in, int in_bytes, void *out, int out_bytes)
 	case Z_STREAM_ERROR:
 		errno = -EINVAL;
 		break;
+	case Z_ERRNO:
+		break;
 	default:
 		errno = -EFAULT;
 		break;
@@ -61,6 +63,8 @@ static int zlib_decompress(const void *in, int in_bytes, void *out, int out_byte
 	case Z_DATA_ERROR:
 		errno = -EINVAL;
 		break;
+	case Z_ERRNO:
+		break;
 	default:
 		errno = -EFAULT;
 		break;
-- 
2.34.1