--- CV/CV.xs	2021/04/10 03:32:09	1.59
+++ CV/CV.xs	2021/11/28 23:26:51	1.63
@@ -420,10 +420,7 @@
         STRLEN data_len;
         U8 *data = SvPVbyte (image_data, data_len);
         static const unsigned char jxl_header[] = {
-              0,    0,    0, 0x0c, 0x4a, 0x58, 0x4c, 0x20,
-           0x0d,  0xa, 0x87, 0x0a,    0,    0,    0, 0x14,
-           0x66, 0x74, 0x79, 0x70, 0x6a, 0x78, 0x6c, 0x20,
-              0,    0,    0,    0, 0x6a, 0x78, 0x6c, 0x20,
+           0, 0, 0, 0x0c, 0x4a, 0x58, 0x4c, 0x20, 0x0d, 0xa, 0x87, 0x0a
         };
 
         if (data_len >= 20
@@ -452,7 +449,42 @@
             && data[ 7] == 0x0a)
           RETVAL = "image/png";
         else if (data_len >= sizeof (jxl_header) && memcmp (data, jxl_header, sizeof (jxl_header)) == 0)
+          RETVAL = "image/jxl"; // todo: might want to use JxlSignatureCheck
+        else if (data_len >= 2
+            && data[0] == 0xff
+            && data[1] == 0x0a)
           RETVAL = "image/jxl";
+        else if (data_len >= 13
+                 && data[0] == 'G'
+                 && data[1] == 'I'
+                 && data[2] == 'F'
+                 && data[3] == '8'
+                 //&& (data[4] == '7' || data[4] == '9')
+                 && data[5] == 'a')
+          {
+            RETVAL = "image/gif";
+
+            // now see if its animated - we require the netscape application header for this
+            int ofs = 13;
+
+            if (data[10] & 0x80)
+              ofs += (1 << ((data[10] & 7) + 1)) * 3;
+
+            if (data_len >= ofs + 2 + 1 + 11)
+              {
+
+                // skip a graphic control extension block. we assume
+                // there is at most one such block - while the NAB
+                // has to come firstz, some files do not obey this
+                if (data[ofs] == 0x21 && data[ofs + 1] == 0xf9)
+                  ofs += 3 + data[ofs + 2] + 1;
+
+                if (data_len >= ofs + 2 + 1 + 11)
+                  if (!memcmp (data + ofs, "\x21\xff\x0bNETSCAPE2.0", sizeof ("\x21\xff\x0bNETSCAPE2.0") - 1))
+                    RETVAL = "video/gif";
+              }
+          }
+
         else
           XSRETURN_UNDEF;
 }
@@ -553,17 +585,20 @@
 	CODE:
 {
 #if JXL
-	JxlDecoder *dec = JxlDecoderCreate (0);
+	JxlDecoder *dec;
         JxlBasicInfo info;
         const uint8_t *next_in = (uint8_t *)SvPVbyte_nolen (image_data);
         size_t avail_in = SvCUR (image_data);
         const char *error = 0;
+        JxlDecoderStatus status;
         void *runner = 0;
         struct bmff_box box;
 
+        RETVAL = 0;
+
         perlinterp_release ();
 
-        RETVAL = 0;
+        dec = JxlDecoderCreate (0);
 
         error = "JxlDecoderCreate failed";
         if (!dec)
@@ -571,26 +606,31 @@
 
         runner = JxlThreadParallelRunnerCreate (0, JxlThreadParallelRunnerDefaultNumWorkerThreads ());
 
+        status = JxlDecoderSetParallelRunner (dec, JxlThreadParallelRunner, runner);
         error = "JxlDecoderSetParallelRunner failed";
-        if (JxlDecoderSetParallelRunner (dec, JxlThreadParallelRunner, runner) != JXL_DEC_SUCCESS)
+        if (status != JXL_DEC_SUCCESS)
           goto done;
 
         error = "JxlDecoderSubscribeEvents failed";
-	if (JxlDecoderSubscribeEvents (dec, JXL_DEC_FULL_IMAGE | JXL_DEC_BASIC_INFO) != JXL_DEC_SUCCESS)
+        status = JxlDecoderSubscribeEvents (dec, JXL_DEC_BASIC_INFO | JXL_DEC_FULL_IMAGE);
+	if (status != JXL_DEC_SUCCESS)
           goto done;
 
+        status = JxlDecoderSetInput (dec, next_in, avail_in);
         error = "JxlDecoderSetInput failed";
-        if (JxlDecoderSetInput (dec, next_in, avail_in) != JXL_DEC_SUCCESS)
+        if (status != JXL_DEC_SUCCESS)
           goto done;
 
         for (;;)
           {
-	    JxlDecoderStatus status = JxlDecoderProcessInput (dec);
+	    status = JxlDecoderProcessInput (dec);
 	  
-            printf ("status %d\n",status);
-
             switch (status)
               {
+	        case JXL_DEC_FULL_IMAGE:
+                  error = 0;
+                  goto done;
+
                 case JXL_DEC_ERROR:
                   error = "JxlDecoderProcessInput failed";
                   goto done;
@@ -600,12 +640,14 @@
                   goto done;
 
 	        case JXL_DEC_SUCCESS:
+                  error = "incomplete decode";
                   goto done;
 
-                case JXL_DEC_NEED_IMAGE_OUT_BUFFER:
+                case JXL_DEC_BASIC_INFO:
                   {
+                    status = JxlDecoderGetBasicInfo (dec, &info);
                     error = "JxlDecoderGetBasicInfo failed";
-	            if (JxlDecoderGetBasicInfo (dec, &info) != JXL_DEC_SUCCESS)
+	            if (status != JXL_DEC_SUCCESS)
                       goto done;
 
                     RETVAL = gdk_pixbuf_new (GDK_COLORSPACE_RGB, !!info.alpha_bits, 8, info.xsize, info.ysize);
@@ -620,13 +662,20 @@
                       gdk_pixbuf_get_rowstride (RETVAL)
                     };
 
+                    // cannot use gdk_pixbuf_get_byte_length because that does
+                    // not return the size of the buffer, but the size of the buffer without
+                    // the last padding bytes. the internal buffer is rowstride * ysize,
+                    // and this is what the jxl decoder needs. none of this is documented
+                    // in either library, of course.
+
+                    status = JxlDecoderSetImageOutBuffer (
+                      dec,
+                      &format,
+                      gdk_pixbuf_get_pixels (RETVAL),
+                      gdk_pixbuf_get_rowstride (RETVAL) * info.ysize
+                    );
                     error = "JxlDecoderSetImageOutBuffer failed";
-                    if (JxlDecoderSetImageOutBuffer (
-                          dec,
-                          &format,
-                          gdk_pixbuf_get_pixels (RETVAL),
-                          gdk_pixbuf_get_byte_length (RETVAL)
-                        ) != JXL_DEC_SUCCESS)
+                    if (status != JXL_DEC_SUCCESS)
                       goto done;
                   }
                   break;
@@ -651,7 +700,7 @@
             if (RETVAL)
               g_object_unref (RETVAL);
 
-            croak ("load_jxl: %s", error);
+            croak ("load_jxl: %s (status %d)", error, status);
           }
 #else
 	croak ("load_jxl: jpeg-xl not enabled at compile time");
@@ -853,7 +902,7 @@
 	STRLEN plen;
         U8 *path = (U8 *)SvPV (pathsv, plen);
         U8 *pend = path + plen;
-        U8 dst [plen * 6 * 3], *dstp = dst;
+        U8 dst [plen * 8 * 3], *dstp = dst;
 
         while (path < pend)
           {
@@ -865,11 +914,12 @@
               *dstp++ = *path++ + ('a' - 'A');
             else if (ch >= '0' && ch <= '9')
               {
+                /* version sort, up to 8 digits */
                 STRLEN el, nl = 0;
                 while (*path >= '0' && *path <= '9' && path < pend)
                   path++, nl++;
 
-                for (el = nl; el < 6; el++)
+                for (el = nl; el < 8; el++)
                   *dstp++ = '0';
 
                 memcpy (dstp, path - nl, nl);