Use ‘echo’ safely with ‘\’ or leading ‘-’

POSIX says that ‘echo FOO’ produces implementation-defined output
if FOO contains leading ‘-’, or ‘\’ anywhere, so don’t assume GNU
behavior in that case.
* Makefile.in (removenullpaths): Remove.
(epaths-force): Rewrite to avoid the need for ‘echo’.
(install-etc): Be clearer about escaping the shell metacharacters
‘\’ and ‘$’.
* Makefile.in (install-arch-indep, install-etcdoc):
* admin/charsets/mapconv, admin/merge-gnulib, admin/merge-pkg-config:
* admin/quick-install-emacs, build-aux/gitlog-to-emacslog:
* configure.ac, lib-src/rcs2log, make-dist:
* src/Makefile.in (lisp.mk):
Don’t assume ‘echo’ outputs ‘\’ and leading ‘-’ unscathed.
For example, use ‘printf '%s\n' "$foo"’ rather than ‘echo "$foo"’
if $foo can contain arbitrary characters.
* lisp/Makefile.in (TAGS): Use ‘ls’, not ‘echo’, to avoid ‘\’ issues.
* doc/lispref/two-volume.make (vol1.pdf):
* test/etags/make-src/Makefile (web ftp publish):
Use ‘printf’ rather than ‘echo -e’.

1 files changed, 2 insertions, 3 deletions

diff --git a/admin/charsets/mapconv b/admin/charsets/mapconv
index 32ba6421a86..3747ae2ad77 100755
--- a/admin/charsets/mapconv
+++ b/admin/charsets/mapconv
@@ -64,7 +64,7 @@ case "$3" in
     KANJI-DATABASE)
 	SOURCE="http://kanji-database.cvs.sourceforge.net/viewvc/*checkout*/kanji-database/kanji-database/data/cns2ucsdkw.txt?revision=1.4";;
     *)
-	echo "Unknown file type: $3";
+	printf 'Unknown file type: %s\n' "$3"
 	exit 1;;
 esac
 
@@ -147,7 +147,6 @@ elif [ "$3" = "KANJI-DATABASE" ] ; then
 	| sed -e 's/...\(....\) U+\([0-9A-F]*\).*/0x\1 0x\2/' \
 	| sort | ${AWKPROG}
 else
-    echo "Invalid arguments: $3"
+    printf 'Invalid arguments: %s\n' "$3"
     exit 1
 fi
-