Avoid adding empty gzip member after gzflush with Z_FINISH.

1 files changed, 10 insertions, 2 deletions

diff --git a/gzwrite.c b/gzwrite.c
index 5b12805..b98022e 100644
--- a/gzwrite.c
+++ b/gzwrite.c
@@ -91,6 +91,15 @@ static int gz_comp(gz_state *state, int flush) {
         return 0;
     }
 
+    /* check for a pending reset */
+    if (state->reset) {
+        /* don't start a new gzip member unless there is data to write */
+        if (strm->avail_in == 0)
+            return 0;
+        PREFIX(deflateReset)(strm);
+        state->reset = 0;
+    }
+
     /* run deflate() on provided input until it produces no more output */
     ret = Z_OK;
     do {
@@ -122,8 +131,7 @@ static int gz_comp(gz_state *state, int flush) {
 
     /* if that completed a deflate stream, allow another to start */
     if (flush == Z_FINISH)
-        PREFIX(deflateReset)(strm);
-
+        state->reset = 1;
     /* all done, no errors */
     return 0;
 }