Merge pull request #4034 from cgohlke/patch-1

Initialize rows_per_strip when RowsPerStrip tag is missing

Author: radarhere

Tests/images/no_rows_per_strip.tif

@@ -832,6 +832,13 @@ def test_old_style_jpeg(self):
             im, "Tests/images/old-style-jpeg-compression.png"
         )
 
+    def test_no_rows_per_strip(self):
+        # This image does not have a RowsPerStrip TIFF tag
+        infile = "Tests/images/no_rows_per_strip.tif"
+        im = Image.open(infile)
+        im.load()
+        self.assertEqual(im.size, (950, 975))
+
     def test_orientation(self):
         base_im = Image.open("Tests/images/g4_orientation_1.tif")
 

Tests/test_file_libtiff.py

@@ -405,8 +405,12 @@ int ImagingLibTiffDecode(Imaging im, ImagingCodecState state, UINT8* buffer, Py_
         UINT32 strip_row, row_byte_size;
         UINT8 *new_data;
         UINT32 rows_per_strip;
+        int ret;
 
-        TIFFGetField(tiff, TIFFTAG_ROWSPERSTRIP, &rows_per_strip);
+        ret = TIFFGetField(tiff, TIFFTAG_ROWSPERSTRIP, &rows_per_strip);
+        if (ret != 1) {
+            rows_per_strip = state->ysize;
+        }
         TRACE(("RowsPerStrip: %u \n", rows_per_strip));
 
         // We could use TIFFStripSize, but for YCbCr data it returns subsampled data size