JPEG: ReadXMPMetadata(): only stop looking for XMP marker at Start Of…

… Scan Some images have XMP after the quantization/Huffman table markers
rouault · Mar 18, 2024 · 0087b66 · 0087b66
1 parent 634ecf0
commit 0087b66
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Showing 3 changed files with 7 additions and 4 deletions.
diff --git a/autotest/gdrivers/data/jpeg/byte_with_xmp_before_soc.jpg b/autotest/gdrivers/data/jpeg/byte_with_xmp_before_soc.jpg
diff --git a/autotest/gdrivers/xmp.py b/autotest/gdrivers/xmp.py
@@ -44,6 +44,7 @@
     ["GIF", "data/gif/byte_with_xmp.gif", True],
     ["BIGGIF", "data/gif/fakebig.gif", False],
     ["JPEG", "data/jpeg/byte_with_xmp.jpg", True],
+    ["JPEG", "data/jpeg/byte_with_xmp_before_soc.jpg", True],
     ["JPEG", "data/jpeg/rgbsmall_rgb.jpg", False],
     ["PNG", "data/png/byte_with_xmp.png", True],
     ["PNG", "data/png/test.png", False],

diff --git a/frmts/jpeg/jpgdataset.cpp b/frmts/jpeg/jpgdataset.cpp
@@ -328,12 +328,14 @@ void JPGDatasetCommon::ReadXMPMetadata()
             break;
 
         nChunkLoc += 2 + abyChunkHeader[2] * 256 + abyChunkHeader[3];
-        // COM marker.
-        if (abyChunkHeader[0] == 0xFF && abyChunkHeader[1] == 0xFE)
+
+        // Not a marker
+        if (abyChunkHeader[0] != 0xFF)
             continue;
 
-        if (abyChunkHeader[0] != 0xFF || (abyChunkHeader[1] & 0xf0) != 0xe0)
-            break;  // Not an APP chunk.
+        // Stop on Start of Scan
+        if (abyChunkHeader[1] == 0xDA)
+            break;
 
         if (abyChunkHeader[1] == APP1_BYTE &&
             memcmp(reinterpret_cast<char *>(abyChunkHeader) + JFIF_MARKER_SIZE,