Merge remote-tracking branch 'origin/7.28' into 7.28

ChangeLog

@@ -1,3 +1,5 @@
+13/3/12 started 7.28.2
+
 13/3/12 started 7.28.1
 - add ICC profile read/write for png files
 

configure.in

@@ -2,7 +2,7 @@
 
 # also update the version number in the m4 macros below
 
-AC_INIT(vips, 7.28.1, vipsip@jiscmail.ac.uk)
+AC_INIT(vips, 7.28.2, vipsip@jiscmail.ac.uk)
 # required for gobject-introspection
 AC_PREREQ(2.62)
 
@@ -15,7 +15,7 @@ AC_CONFIG_MACRO_DIR([m4])
 # user-visible library versioning
 m4_define([vips_major_version], [7])
 m4_define([vips_minor_version], [28])
-m4_define([vips_micro_version], [1])
+m4_define([vips_micro_version], [2])
 m4_define([vips_version],
           [vips_major_version.vips_minor_version.vips_micro_version])
 
@@ -35,7 +35,7 @@ VIPS_VERSION_STRING=$VIPS_VERSION-`date`
 #   interface changes not backwards compatible?: reset age to 0
 
 LIBRARY_CURRENT=31
-LIBRARY_REVISION=1
+LIBRARY_REVISION=2
 LIBRARY_AGE=16
 
 # patched into include/vips/version.h

libvips/foreign/vipspng.c

@@ -69,8 +69,8 @@
  */
 
 /*
- */
 #define DEBUG
+ */
 
 #ifdef HAVE_CONFIG_H
 #include <config.h>
@@ -259,13 +259,24 @@ png2vips_header( Read *read, VipsImage *out )
 			interpretation = VIPS_INTERPRETATION_sRGB;
 	}
 
-	/* Expand palette images, expand transparency too.
+	/* Expand palette images.
 	 */
 	if( color_type == PNG_COLOR_TYPE_PALETTE )
 		png_set_palette_to_rgb( read->pPng );
-	if( png_get_valid( read->pPng, read->pInfo, PNG_INFO_tRNS ) ) 
+
+	/* Expand transparency images too.
+	 */
+	if( png_get_valid( read->pPng, read->pInfo, PNG_INFO_tRNS ) ) {
 		png_set_tRNS_to_alpha( read->pPng );
 
+		/* Some PNGs have an alpha but do not set color_type correctly
+		 * .. make sure we add space for an alpha.
+		 */
+		if( color_type == PNG_COLOR_TYPE_GRAY ||
+			color_type == PNG_COLOR_TYPE_RGB )
+			bands += 1;
+	}
+
 	/* Expand <8 bit images to full bytes.
 	 */
 	if( color_type == PNG_COLOR_TYPE_GRAY &&