bug#10626: Should configure fail if pkg-config fails?

[Paul Eggert]

On 01/24/2012 06:15 PM, Jordi Gutiérrez Hermoso wrote:
> it shouldn't assume that GTK+ is working correctly if
> pkg-config returns nonzero exit status.

True enough.  Here's a proposed patch, which I'd like to
install into the trunk.  I'm CC'ing this to bug-gnu-emacs
instead of to emacs-devel, so that it has a proper bug number.


=== modified file 'ChangeLog'
--- ChangeLog   2012-01-19 07:21:25 +0000
+++ ChangeLog   2012-01-28 09:04:13 +0000
@@ -1,3 +1,11 @@
+2012-01-28  Paul Eggert  <eggert@cs.ucla.edu>
+
+       Check pkg-config exit status when configuring.
+       * configure.in (PKG_CHECK_MODULES): Do not assume that pkg-config
+       works; check its exit status.  Problem reported by Jordi Gutiérrez
+       Hermoso in
+       <http://lists.gnu.org/archive/html/emacs-devel/2012-01/msg00787.html>.
+
 2012-01-16  Juanma Barranquero  <lekktu@gmail.com>
 
        * .bzrignore: Ignore etc/__pycache__.

=== modified file 'configure.in'
--- configure.in        2012-01-19 07:21:25 +0000
+++ configure.in        2012-01-28 09:04:13 +0000
@@ -1124,17 +1124,14 @@
      if $PKG_CONFIG --atleast-pkgconfig-version $PKG_CONFIG_MIN_VERSION; then
         AC_MSG_CHECKING(for $2)
 
-        if $PKG_CONFIG --exists "$2" 2>&AS_MESSAGE_LOG_FD; then
-            AC_MSG_RESULT(yes)
+        if $PKG_CONFIG --exists "$2" 2>&AS_MESSAGE_LOG_FD &&
+          $1_CFLAGS=`$PKG_CONFIG --cflags "$2" 2>&AS_MESSAGE_LOG_FD` &&
+          $1_LIBS=`$PKG_CONFIG --libs "$2" 2>&AS_MESSAGE_LOG_FD`; then
+
+           $1_CFLAGS=`AS_ECHO(["$$1_CFLAGS"]) | sed -e 's,///*,/,g'`
+           $1_LIBS=`AS_ECHO(["$$1_LIBS"]) | sed -e 's,///*,/,g'`
+            AC_MSG_RESULT([yes CFLAGS='$$1_CFLAGS' LIBS='$$1_LIBS'])
             succeeded=yes
-
-            AC_MSG_CHECKING($1_CFLAGS)
-            $1_CFLAGS=`$PKG_CONFIG --cflags "$2"|sed -e 's,///*,/,g'`
-            AC_MSG_RESULT($$1_CFLAGS)
-
-            AC_MSG_CHECKING($1_LIBS)
-            $1_LIBS=`$PKG_CONFIG --libs "$2"|sed -e 's,///*,/,g'`
-            AC_MSG_RESULT($$1_LIBS)
         else
             AC_MSG_RESULT(no)
             $1_CFLAGS=""