build: support --program-prefix etc.

Problem reported by Antonio Diaz Diaz via Dagobert Michelsen in:
https://bugs.gnu.org/16876
* Makefile.am (.in): Substitute for 'gzip', 'zdiff', 'zgrep'.
($(GZIP_TRANSFORMED), $(ZDIFF_TRANSFORMED), $(ZGREP_TRANSFORMED)):
New rules to build forwarding shell scripts, if needed.
Add these files to BUILT_SOURCES and MOSTLY_CLEANFILES if needed.
* configure.ac (GZIP_TRANSFORMED, ZDIFF_TRANSFORMED, ZGREP_TRANSFORMED):
New substituted vars.
(GZIP_IS_TRANSFORMED, ZDIFF_IS_TRANSFORMED, ZGREP_IS_TRANSFORMED):
New Automake conditions.
* gunzip.in, gzexe.in, zcat.in, zcmp.in, zdiff.in, zegrep.in:
* zfgrep.in, zforce.in, zgrep.in, zless.in, zmore.in, znew.in:
Quote possibly-transformed subcommand names.

1 files changed, 1 insertions, 1 deletions

diff --git a/zmore.in b/zmore.in
index 01fa7e8..bd007b4 100644
--- a/zmore.in
+++ b/zmore.in
@@ -50,5 +50,5 @@ for FILE
 do
   test $# -lt 2 ||
     printf '::::::::::::::\n%s\n::::::::::::::\n' "$FILE" || break
-  gzip -cdfq -- "$FILE"
+  'gzip' -cdfq -- "$FILE"
 done 2>&1 | eval ${PAGER-more}