textord: Catch empty rows in block iterator (fixes #4039)

When textord_blockndoc_fixed was set to 1 empty rows caused a segmentation fault. Test also textord_blockndoc_fixed first because it is typically 0. Signed-off-by: Stefan Weil <[email protected]>
tesseract-ocr · Mar 24, 2023 · 1569e50 · 1569e50
1 parent 691de2b
commit 1569e50
Showing 1 changed file with 2 additions and 3 deletions.
diff --git a/src/textord/topitch.cpp b/src/textord/topitch.cpp
@@ -398,9 +398,8 @@ bool try_doc_fixed(             // determine pitch
   int16_t mid_cuts; // no of cheap cuts
   float pitch_sd;   // sync rating
 
-  if (block_it.empty()
-      //      || block_it.data()==block_it.data_relative(1)
-      || !textord_blockndoc_fixed) {
+  if (!textord_blockndoc_fixed ||
+      block_it.empty() || block_it.data()->get_rows()->empty()) {
     return false;
   }
   shift_factor = gradient / (gradient * gradient + 1);