From f7ee9d5c1c75e3b9a005fc0652c82f92b1e8a2e9 Mon Sep 17 00:00:00 2001
From: tsteven4 <tsteven4@gmail.com>
Date: Mon, 28 Apr 2014 22:23:05 +0000
Subject: [PATCH] work around bug with gbfseek that results in premature eof
 indications on uncompressed input on the windows platform.

---
 gpsbabel/gbfile.cc            |  2 --
 gpsbabel/zlib/README.gpsbabel |  6 +++++-
 gpsbabel/zlib/gzlib.c         |  5 ++++-
 gpsbabel/zlib/gzlib.patch     | 14 ++++++++++++++
 4 files changed, 23 insertions(+), 4 deletions(-)
 create mode 100644 gpsbabel/zlib/gzlib.patch

diff --git a/gpsbabel/gbfile.cc b/gpsbabel/gbfile.cc
index 1b5d3f542..a5ae1f120 100644
--- a/gpsbabel/gbfile.cc
+++ b/gpsbabel/gbfile.cc
@@ -21,7 +21,6 @@
  */
 
 #include "defs.h"
-#include "zlib/zconf.h"
 #include "gbfile.h"
 
 #include <assert.h>
@@ -29,7 +28,6 @@
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <QtCore/QDebug>
 
 
 #if __WIN32__
diff --git a/gpsbabel/zlib/README.gpsbabel b/gpsbabel/zlib/README.gpsbabel
index b6d1e957c..350f999a6 100644
--- a/gpsbabel/zlib/README.gpsbabel
+++ b/gpsbabel/zlib/README.gpsbabel
@@ -1 +1,5 @@
-Unmodified wubset of zlib-1.2.8 from zlib.net.
+modified subset of zlib-1.2.8 from zlib.net.
+1.  zconf.h is modified to include our config.h
+2.  gzlib.c is modified to resolve a seek problem with uncompressed files on windows platforms build with mingw32 gcc.
+see gzlib.patch
+
diff --git a/gpsbabel/zlib/gzlib.c b/gpsbabel/zlib/gzlib.c
index fae202ef8..64ca8db37 100644
--- a/gpsbabel/zlib/gzlib.c
+++ b/gpsbabel/zlib/gzlib.c
@@ -393,7 +393,10 @@ z_off64_t ZEXPORT gzseek64(file, offset, whence)
     /* if within raw area while reading, just go there */
     if (state->mode == GZ_READ && state->how == COPY &&
             state->x.pos + offset >= 0) {
-        ret = LSEEK(state->fd, offset - state->x.have, SEEK_CUR);
+/* Start GPSBabel local */
+/*      ret = LSEEK(state->fd, offset - state->x.have, SEEK_CUR); */
+        ret = LSEEK(state->fd, offset - (z_off64_t)state->x.have, SEEK_CUR);
+/* end GPSBabel local */
         if (ret == -1)
             return -1;
         state->x.have = 0;
diff --git a/gpsbabel/zlib/gzlib.patch b/gpsbabel/zlib/gzlib.patch
new file mode 100644
index 000000000..7651203bd
--- /dev/null
+++ b/gpsbabel/zlib/gzlib.patch
@@ -0,0 +1,14 @@
+--- gzlib.c	2014-04-28 16:19:19.839086477 -0600
++++ gzlib.patch.c	2014-04-28 16:18:31.220835104 -0600
+@@ -393,7 +393,10 @@
+     /* if within raw area while reading, just go there */
+     if (state->mode == GZ_READ && state->how == COPY &&
+             state->x.pos + offset >= 0) {
+-        ret = LSEEK(state->fd, offset - state->x.have, SEEK_CUR);
++/* Start GPSBabel local */
++/*      ret = LSEEK(state->fd, offset - state->x.have, SEEK_CUR); */
++        ret = LSEEK(state->fd, offset - (z_off64_t)state->x.have, SEEK_CUR);
++/* end GPSBabel local */
+         if (ret == -1)
+             return -1;
+         state->x.have = 0;
-- 
2.30.2