Add support for .svgz files to svgload

libvips/foreign/svgload.c

@@ -54,6 +54,16 @@
 
 #include <cairo.h>
 #include <librsvg/rsvg.h>
+/* Old librsvg versions don't include librsvg-features.h by default,
+ * while newer versions deprecate direct inclusion.
+ */
+#ifndef LIBRSVG_FEATURES_H
+#include <librsvg/librsvg-features.h>
+#endif
+
+#if LIBRSVG_CHECK_FEATURE(SVGZ) && defined(HAVE_ZIP)
+#include <zlib.h>
+#endif
 
 typedef struct _VipsForeignLoadSvg {
 	VipsForeignLoad parent_object;
@@ -315,6 +325,9 @@ vips_foreign_load_svg_file_header( VipsForeignLoad *load )
 
 static const char *vips_foreign_svg_suffs[] = {
 	".svg",
+#if LIBRSVG_CHECK_FEATURE(SVGZ)
+	".svgz",
+#endif
 	NULL
 };
 
@@ -364,13 +377,66 @@ typedef VipsForeignLoadSvgClass VipsForeignLoadSvgBufferClass;
 G_DEFINE_TYPE( VipsForeignLoadSvgBuffer, vips_foreign_load_svg_buffer, 
 	vips_foreign_load_svg_get_type() );
 
+#if LIBRSVG_CHECK_FEATURE(SVGZ) && defined(HAVE_ZIP)
+static void *
+vips_zalloc( void *opaque, unsigned items, unsigned size )
+{
+	return( g_malloc0_n( items, size ) );
+}
+
+static void
+vips_zfree( void *opaque, void *ptr )
+{
+	return( g_free( ptr ) );
+}
+#endif
+
 static gboolean
 vips_foreign_load_svg_is_a_buffer( const void *buf, size_t len )
 {
-	char *str = (char *) buf;
+	unsigned char *str = (unsigned char *) buf;
 
 	int i;
 
+#if LIBRSVG_CHECK_FEATURE(SVGZ) && defined(HAVE_ZIP)
+	/* Check for SVGZ gzip signature and inflate.
+	 * Minimum gzip size is 18 bytes, starting with 1F 8B.
+	 */
+	if( len >= 18 && str[0] == 0x1f && str[1] == 0x8b ) {
+		z_stream zs;
+		size_t opos = 0;
+		unsigned char obuf[224];
+
+		zs.zalloc = (alloc_func) vips_zalloc;
+		zs.zfree = (free_func) vips_zfree;
+		zs.opaque = Z_NULL;
+		zs.next_in = str;
+		zs.avail_in = len;
+
+		if( inflateInit2(&zs, 15 | 32) != Z_OK ) {
+			vips_error( "svgload",
+				"%s", _( "Zlib init failed" ) );
+			return( -1 );
+		}
+
+		do {
+			zs.avail_out = sizeof(obuf) - opos;
+			zs.next_out = obuf + opos;
+			if( inflate(&zs, Z_NO_FLUSH) < Z_OK ) {
+				vips_error( "svgload",
+					"%s", _( "Zlib inflate failed" ) );
+				return( -1 );
+			}
+			opos = sizeof(obuf) - zs.avail_out;
+		} while( opos < sizeof(obuf) && zs.avail_out == 0 );
+
+		inflateEnd(&zs);
+
+		str = obuf;
+		len = opos;
+	}
+#endif
+
 	/* SVG documents are very freeform. They normally look like:
 	 *
 	 * <?xml version="1.0" encoding="UTF-8"?>
@@ -393,12 +459,7 @@ vips_foreign_load_svg_is_a_buffer( const void *buf, size_t len )
 			return( 0 );
 
 	for( i = 0; i < 200 && i < len - 5; i++ ) {
-		char txt[5];
-
-		/* 5, since we include the \0 at the end.
-		 */
-		vips_strncpy( txt, buf + i, 5 );
-		if( strcasecmp( txt, "<svg" ) == 0 )
+		if( strncmp( (const char *) str + i, "<svg", 4 ) == 0 )
 			return( 1 );
 	}
 

test/test_foreign.py

@@ -50,6 +50,7 @@ class TestForeign(unittest.TestCase):
         self.pdf_file = "images/ISO_12233-reschart.pdf"
         self.cmyk_pdf_file = "images/cmyktest.pdf"
         self.svg_file = "images/vips-profile.svg"
+        self.svgz_file = "images/vips-profile.svgz"
 
         self.colour = Vips.Image.jpegload(self.jpeg_file)
         self.mono = self.colour.extract_band(1)
@@ -499,6 +500,9 @@ class TestForeign(unittest.TestCase):
         self.file_loader("svgload", self.svg_file, svg_valid)
         self.buffer_loader("svgload_buffer", self.svg_file, svg_valid)
 
+        self.file_loader("svgload", self.svgz_file, svg_valid)
+        self.buffer_loader("svgload_buffer", self.svgz_file, svg_valid)
+
         im = Vips.Image.new_from_file(self.svg_file)
         x = Vips.Image.new_from_file(self.svg_file, scale = 2)
         self.assertLess(abs(im.width * 2 - x.width), 2)