fix build against libpng15

plotutils-2.6-png15.patch

@@ -0,0 +1,39 @@
+diff -up plotutils-2.6/libplot/z_write.c.png15 plotutils-2.6/libplot/z_write.c
+--- plotutils-2.6/libplot/z_write.c.png15	2008-07-15 20:54:10.000000000 -0400
++++ plotutils-2.6/libplot/z_write.c	2012-03-22 13:26:48.251676137 -0400
+@@ -164,7 +164,11 @@ _pl_z_maybe_output_image (S___(Plotter *
+     }
+ 
+   /* cleanup after libpng errors (error handler does a longjmp) */
++#if PNG_LIBPNG_VER_MAJOR >= 1 && PNG_LIBPNG_VER_MINOR >= 4
++  if (setjmp (png_jmpbuf(png_ptr)))
++#else
+   if (setjmp (png_ptr->jmpbuf))
++#endif
+     {
+       png_destroy_write_struct (&png_ptr, (png_info **)NULL);
+       return -1;
+@@ -444,7 +448,11 @@ _our_error_fn_stdio (png_struct *png_ptr
+ #endif
+     }
+ 
++#if PNG_LIBPNG_VER_MAJOR >= 1 && PNG_LIBPNG_VER_MINOR >= 4
++  longjmp (png_jmpbuf(png_ptr), 1);
++#else
+   longjmp (png_ptr->jmpbuf, 1);
++#endif
+ }
+ 
+ static void 
+@@ -515,7 +523,11 @@ _our_error_fn_stream (png_struct *png_pt
+ #endif
+     }
+ 
++#if PNG_LIBPNG_VER_MAJOR >= 1 && PNG_LIBPNG_VER_MINOR >= 4
++  longjmp (png_jmpbuf(png_ptr), 1);
++#else
+   longjmp (png_ptr->jmpbuf, 1);
++#endif
+ }
+ 
+ static void 

plotutils.spec

@@ -1,14 +1,14 @@
 
 Name:      plotutils
 Version:   2.6
-Release:   3%{?dist}
+Release:   4%{?dist}
 Summary:   GNU vector and raster graphics utilities and libraries
 
 Group:     Applications/Productivity
 License:   GPLv2+
 URL:       http://www.gnu.org/software/plotutils/
 Source0:   ftp://ftp.gnu.org/gnu/plotutils/plotutils-%{version}.tar.gz
-
+Patch0:    plotutils-2.6-png15.patch
 BuildRequires:   flex
 BuildRequires:   libpng-devel
 BuildRequires:   xorg-x11-proto-devel
@@ -43,6 +43,7 @@ applications
 
 %prep
 %setup -q
+%patch0 -p1 -b .png15
 
 
 %build
@@ -109,6 +110,9 @@ fi
 
 
 %changelog
+* Thu Mar 22 2012 Tom Callaway <spot@fedoraproject.org> - 2.6-4
+- fix build against libpng15
+
 * Sat Jan 14 2012 Fedora Release Engineering <rel-eng@lists.fedoraproject.org> - 2.6-3
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_17_Mass_Rebuild