[Zlib-devel] zlib 1.2.3.4 Winter Solstice Edition

[Vincent Torri]

Hey,

about the Windows CE port: on Windows CE, file descriptors are HANDLE in 
disguise and a negative value can be a valid 'file descriptor'. So 
checking for fd that are negative is not correct. Checking with -1 is 
better, i think.

See gzio.c, lines 195 and 253. If you think there's no problem elsewhere 
(afaik, open() returns -1 on error, and fileno never fails (or has an 
undefined behavior if the stream is not valid)). In addition it is what is 
described in the comment of gz_open(), line 104.

Here is the patch:

--- gzio.c	2009-12-22 07:43:16.000000000 +0100
+++ gzio.c.new	2009-12-28 18:20:15.000000000 +0100
@@ -192,7 +192,7 @@
      s->stream.avail_out = Z_BUFSIZE;

      errno = 0;
-    s->file = fd < 0 ? (use64 ? F_OPEN64(path, fmode) : F_OPEN(path, fmode)) :
+    s->file = fd == -1 ? (use64 ? F_OPEN64(path, fmode) : F_OPEN(path, fmode)) :
                (FILE*)fdopen(fd, fmode);

      if (s->file == NULL) {
@@ -250,7 +250,7 @@
  {
      char name[46];      /* allow for up to 128-bit integers */

-    if (fd < 0) return (gzFile)Z_NULL;
+    if (fd == -1) return (gzFile)Z_NULL;
      sprintf(name, "<fd:%d>", fd); /* for debugging */

      return gz_open (name, mode, fd, 0);