Avoid AC_PREPROC_IFELSE glitch in configure.ac

Problem reported by Angelo Graziosi in:
http://lists.gnu.org/archive/html/emacs-devel/2016-04/msg00545.html
* configure.ac (gl_gcc_warnings): Work around an Autoconf glitch:
AC_PREPROC_IFELSE doesn’t generate a simple shell command.

diff --git a/configure.ac b/configure.ac
index dbb5ad27c9b74a956338f98c34e52121ad531d37..1cd9017d19fec57469e73f19ed413328469f3e30 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -879,8 +879,9 @@ AC_ARG_ENABLE([gcc-warnings],
    # however, if there is also a .tarball-version file it is probably
    # just a release imported into Git for patch management.
    gl_gcc_warnings=no
-   test -e "$srcdir"/.git && test ! -f "$srcdir"/.tarball-version &&
+   if test -e "$srcdir"/.git && test ! -f "$srcdir"/.tarball-version; then
      gl_GCC_VERSION_IFELSE([5], [3], [gl_gcc_warnings=warn-only])]
+   fi
 )
 
 # clang is unduly picky about some things.