Merge branch '8.10'

ChangeLog

@@ -10,6 +10,9 @@
 - add _source load support for pdfium
 - add "seed" param to perlin, worley and gaussnoise
 
+14/12/20 started 8.10.4
+- fix spng detection
+
 18/10/20 started 8.10.3
 - relax heic is_a rules [hisham]
 - fix vips7 webp load [barryspearce]

configure.ac

@@ -1149,21 +1149,31 @@ FIND_GIFLIB(
 )
 
 # Look for libspng first
+# 0.6.1 uses "libspng.pc", git master libspng uses "spng.pc"
 AC_ARG_WITH([libspng], 
   AS_HELP_STRING([--without-libspng], [build without libspng (default: test)]))
 
 if test x"$with_libspng" != x"no"; then
-  PKG_CHECK_MODULES(SPNG, spng >= 0.6,
+  PKG_CHECK_MODULES(SPNG, libspng >= 0.6,
     [AC_DEFINE(HAVE_SPNG,1,[define if you have libspng installed.])
      with_libspng=yes
-     PACKAGES_USED="$PACKAGES_USED spng"
+     PACKAGES_USED="$PACKAGES_USED libspng"
     ],
-    [with_libspng=no
+    [PKG_CHECK_MODULES(SPNG, spng >= 0.6,
+      [AC_DEFINE(HAVE_SPNG,1,[define if you have libspng installed.])
+       with_libspng=yes
+       PACKAGES_USED="$PACKAGES_USED spng"
+      ],
+      [with_libspng=no
+      ]
+     )
     ]
   )
 fi
 
 # look for PNG with pkg-config ... fall back to our tester
+# we can have both PNG and SPNG enabled, with SPNG for read and PNG for
+# write
 AC_ARG_WITH([png], 
   AS_HELP_STRING([--without-png], [build without libpng (default: test)]))
 

doc/libvips-docs.xml.in

@@ -9,10 +9,9 @@
   <bookinfo>
     <title>libvips Reference Manual</title>
     <releaseinfo>
-      For libvips @VIPS_VERSION@.
-      The latest version of this documentation can be found on the 
-      <ulink role="online-location"
-        url="http://libvips.github.io/libvips/API/current/">libvips website</ulink>.
+      For VIPS @VIPS_VERSION@. The latest version of this documentation can be 
+      found on the <ulink role="online-location" url="/libvips">VIPS 
+      website</ulink>.
     </releaseinfo>
   </bookinfo>