zlib/backport-Avoid-adding-empty-gzip-member-after-gzflush-with-Z_FINISH.patch
zhoupengcheng fce1c5536a zlib:backport upstream patch
(cherry picked from commit ee65ab90886d1240dc7ef6b6afc98012d7c18b2a)
2024-05-07 19:57:31 +08:00

68 lines
2.3 KiB
Diff

From 79baebe50e4d6b73ae1f8b603f0ef41300110aa3 Mon Sep 17 00:00:00 2001
From: Mark Adler <madler@alumni.caltech.edu>
Date: Sat, 13 Apr 2019 17:05:16 -0700
Subject: [PATCH] Avoid adding empty gzip member after gzflush with Z_FINISH.
Reference:https://github.com/madler/zlib/commit/79baebe50e4d6b73ae1f8b603f0ef41300110aa3
Conflict:NA
---
gzguts.h | 1 +
gzlib.c | 2 ++
gzwrite.c | 11 ++++++++++-
3 files changed, 13 insertions(+), 1 deletion(-)
diff --git a/gzguts.h b/gzguts.h
index 6378d468a..fc712dc4d 100644
--- a/gzguts.h
+++ b/gzguts.h
@@ -190,6 +190,7 @@ typedef struct {
/* 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 4838bf047..f6b3b406e 100644
--- a/gzlib.c
+++ b/gzlib.c
@@ -81,6 +81,8 @@ local void gz_reset(state)
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 52381332e..85b576ba3 100644
--- a/gzwrite.c
+++ b/gzwrite.c
@@ -97,6 +97,15 @@ local int gz_comp(state, 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;
+ deflateReset(strm);
+ state->reset = 0;
+ }
+
/* run deflate() on provided input until it produces no more output */
ret = Z_OK;
do {
@@ -134,7 +143,7 @@ local int gz_comp(state, flush)
/* 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;