bug#33842: [PATCH] build: avoid build failure with --enable-gcc-warnings and latest gcc

[Jim Meyering]

FYI, I noticed a build failure and fixed it with the change below.

I've also pushed three more patches:
  build: make the autoconf-2.63 requirement explicit
  maint: update gnulib to latest; also update bootstrap and init.sh
  maint: improve a comment

* gzip.c (do_list): There was a loop to compute the maximum width
of a decimal positive off_t value. Replace it with assignment to a
constant.  Noticed because gcc 9.0.0 20181219 warned about its use
as a printf format-width value.
(OFF_T_MAX): Remove now-unused definition.
---
 gzip.c | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/gzip.c b/gzip.c
index e6a7761..bef6bc6 100644
--- a/gzip.c
+++ b/gzip.c
@@ -115,10 +115,6 @@ static char const *const license_msg[] = {
   off_t lseek (int fd, off_t offset, int whence);
 #endif

-#ifndef OFF_T_MAX
-# define OFF_T_MAX TYPE_MAXIMUM (off_t)
-#endif
-
 #ifndef HAVE_WORKING_O_NOFOLLOW
 # define HAVE_WORKING_O_NOFOLLOW 0
 #endif
@@ -1737,12 +1733,7 @@ local void do_list(ifd, method)
         "lzh  ",  /* 3 */
         "", "", "", "", /* 4 to 7 reserved */
         "defla"}; /* 8 */
-    int positive_off_t_width = 1;
-    off_t o;
-
-    for (o = OFF_T_MAX;  9 < o;  o /= 10) {
-        positive_off_t_width++;
-    }
+    int positive_off_t_width = INT_BUFSIZE_BOUND (off_t) - 2;

     if (first_time && method >= 0) {
         first_time = 0;