krb5 commit: Add configure option to disable nls support

[Greg Hudson]

https://github.com/krb5/krb5/commit/981ed4105729954fbcd95b8447c5b7e0a7922377
commit 981ed4105729954fbcd95b8447c5b7e0a7922377
Author: Zentaro Kavanagh <zentaro at google.com>
Date:   Tue Dec 20 16:52:01 2016 -0800

    Add configure option to disable nls support
    
    ChromeOS portage disables nls support as users are not expected to see
    strings from the packages built.  Add a configure option to allow
    this.
    
    [ghudson at mit.edu: rewrote commit message, reformatted code]
    
    ticket: 8534 (new)

 src/configure.in |   30 ++++++++++++++++++++++--------
 1 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/src/configure.in b/src/configure.in
index a519a4f..853e7bb 100644
--- a/src/configure.in
+++ b/src/configure.in
@@ -118,15 +118,29 @@ LIBUTIL=-lutil
 ])
 AC_SUBST(LIBUTIL)
 
-AC_CHECK_HEADER(libintl.h, [
-	AC_SEARCH_LIBS(dgettext, intl, [
-		AC_DEFINE(ENABLE_NLS, 1,
-			[Define if translation functions should be used.])])])
-
-AC_CHECK_PROG(MSGFMT,msgfmt,msgfmt)
+# Determine if NLS is desired and supported.
 po=
-if test x"$MSGFMT" != x; then
-	po=po
+AC_ARG_ENABLE([nls],
+AC_HELP_STRING([--disable-nls], [disable native language support]),
+              [], [enable_nls=check])
+if test "$enable_nls" != no; then
+  AC_CHECK_HEADER(libintl.h, [
+    AC_SEARCH_LIBS(dgettext, intl, [
+      AC_DEFINE(ENABLE_NLS, 1,
+                [Define if translation functions should be used.])
+      nls_enabled=yes])])
+
+  AC_CHECK_PROG(MSGFMT,msgfmt,msgfmt)
+  if test x"$MSGFMT" != x; then
+    po=po
+  fi
+
+  # Error out if --enable-nls was explicitly requested but can't be enabled.
+  if test "$enable_nls" = yes; then
+    if test "$nls_enabled" != yes -o "x$po" = x; then
+      AC_MSG_ERROR([NLS support requested but cannot be built])
+    fi
+  fi
 fi
 AC_SUBST(po)