Clean up the usage of z_const and respect const usage within zlib.

This patch allows zlib to compile cleanly with the -Wcast-qual gcc
warning enabled, but only if ZLIB_CONST is defined, which adds
const to next_in and msg in z_stream and in the in_func prototype.
A --const option is added to ./configure which adds -DZLIB_CONST
to the compile flags, and adds -Wcast-qual to the compile flags
when ZLIBGCCWARN is set in the environment.

1 files changed, 1 insertions, 1 deletions

diff --git a/contrib/infback9/infback9.c b/contrib/infback9/infback9.c
index 3691d4a..05fb3e3 100644
--- a/contrib/infback9/infback9.c
+++ b/contrib/infback9/infback9.c
@@ -222,7 +222,7 @@ out_func out;
 void FAR *out_desc;
 {
     struct inflate_state FAR *state;
-    unsigned char FAR *next;    /* next input */
+    z_const unsigned char FAR *next;    /* next input */
     unsigned char FAR *put;     /* next output */
     unsigned have;              /* available input */
     unsigned long left;         /* available output */