Fix build with JPEG-QS but without lcms2

fiv-io.c

@@ -27,20 +27,22 @@
 #include <webp/encode.h>
 #include <webp/mux.h>
 
-// Colour management must be handled before RGB conversions.
-#ifdef HAVE_LCMS2
-#include <lcms2.h>
-#endif  // HAVE_LCMS2
-
 #ifdef HAVE_JPEG_QS
-#include <jpeglib.h>
 #include <setjmp.h>
+#include <stdio.h>
+
+#include <jpeglib.h>
 // This library is tricky to build, simply make it work at all.
 #define NO_SIMD
 #include <jpeg-quantsmooth/quantsmooth.h>
 #undef NO_SIMD
 #endif  // HAVE_JPEG_QS
 
+// Colour management must be handled before RGB conversions.
+#ifdef HAVE_LCMS2
+#include <lcms2.h>
+#endif  // HAVE_LCMS2
+
 #ifdef HAVE_LIBRAW
 #include <libraw.h>
 #endif  // HAVE_LIBRAW
@@ -265,6 +267,7 @@ static void
 trivial_cmyk_to_host_byte_order_argb(unsigned char *p, int len)
 {
 	// This CMYK handling has been seen in gdk-pixbuf/JPEG, GIMP/JPEG, skcms.
+	// It will typically produce horribly oversaturated results.
 	// Assume that all YCCK/CMYK JPEG files use inverted CMYK, as Photoshop
 	// does, see https://bugzilla.gnome.org/show_bug.cgi?id=618096
 	while (len--) {
@@ -1055,6 +1058,10 @@ static cairo_surface_t *
 open_libjpeg_turbo(
 	const gchar *data, gsize len, FivIoProfile profile, GError **error)
 {
+	// Note that there doesn't seem to be much of a point in using this
+	// simplified API anymore, because JPEG-QS needs the original libjpeg API.
+	// It's just more or less duplicated code which won't compile with
+	// the slow version of the library.
 	tjhandle dec = tjInitDecompress();
 	if (!dec) {
 		set_error(error, tjGetErrorStr2(dec));
@@ -2325,7 +2332,7 @@ fiv_io_open(
 
 	cairo_surface_t *surface =
 		fiv_io_open_from_data(data, len, uri, profile, enhance, error);
-	free(data);
+	g_free(data);
 	return surface;
 }