Avoid adding empty gzip member after gzflush with Z_FINISH.
diff --git a/gzguts.h b/gzguts.h
index 6378d46..fc712dc 100644
--- a/gzguts.h
+++ b/gzguts.h
@@ -190,6 +190,7 @@
/* just for writing */
int level; /* compression level */
int strategy; /* compression strategy */
+ int reset; /* true if a reset is pending after a Z_FINISH */
/* seek request */
z_off64_t skip; /* amount to skip (already rewound if backwards) */
int seek; /* true if seek request pending */
diff --git a/gzlib.c b/gzlib.c
index 4838bf0..f6b3b40 100644
--- a/gzlib.c
+++ b/gzlib.c
@@ -81,6 +81,8 @@
state->past = 0; /* have not read past end yet */
state->how = LOOK; /* look for gzip header */
}
+ else /* for writing ... */
+ state->reset = 0; /* no deflateReset pending */
state->seek = 0; /* no seek request pending */
gz_error(state, Z_OK, NULL); /* clear error */
state->x.pos = 0; /* no uncompressed data yet */
diff --git a/gzwrite.c b/gzwrite.c
index 5238133..85b576b 100644
--- a/gzwrite.c
+++ b/gzwrite.c
@@ -97,6 +97,15 @@
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;
+ deflateReset(strm);
+ state->reset = 0;
+ }
+
/* run deflate() on provided input until it produces no more output */
ret = Z_OK;
do {
@@ -134,7 +143,7 @@
/* if that completed a deflate stream, allow another to start */
if (flush == Z_FINISH)
- deflateReset(strm);
+ state->reset = 1;
/* all done, no errors */
return 0;
