[dia] Bug 710379 - [warningectomy] no AC_LANG_SOURCE call detected in body

[Hans Breuer <hans src gnome org>]

commit c6b8415f1be2a965d310ce05f844e0411a23e9aa
Author: Hans Breuer <hans breuer org>
Date:   Sat Oct 19 12:04:51 2013 +0200

    Bug 710379 - [warningectomy] no AC_LANG_SOURCE call detected in body
    
    Probably we can get rid of the detailed PNG source check nowadays,
    but just adding AC_LANG_SOURCE is easier.

 configure.in |   11 ++++++-----
 1 files changed, 6 insertions(+), 5 deletions(-)
---
diff --git a/configure.in b/configure.in
index fe28e7b..8a533b3 100644
--- a/configure.in
+++ b/configure.in
@@ -216,13 +216,14 @@ if test "$png_ok" = yes; then
   dnl Why can't AC_LINK_IFELSE take extra libs?
   old_LDFLAGS="${LDFLAGS}"
   LDFLAGS="${LDFLAGS} -lz -lm"
-  AC_LINK_IFELSE([#include <png.h>
-                  png_structp pp;
+  AC_LINK_IFELSE([AC_LANG_SOURCE([
+                 #include <png.h>
+                 png_structp pp;
                  png_infop info; 
                  png_colorp cmap; 
-                 main() { void*foo = png_create_read_struct; }],
-                 png_ok=yes,
-                 png_ok=no)
+                 main() { void*foo = png_create_read_struct; }])],
+                 [png_ok=yes],
+                 [png_ok=no])
   LDFLAGS="${old_LDFLAGS}"
   AC_MSG_RESULT($png_ok)
   if test "$png_ok" = yes; then