Merge pull request #4563 from gaurav0107/fix/4448-crash-upon-processing-input-file-with-di

Fix crash when LSTM is missing in disabled-legacy build (#4448)

Author: amitdo

src/ccmain/tessedit.cpp

@@ -171,8 +171,19 @@ bool Tesseract::init_tesseract_lang_data(const std::string &language, OcrEngineM
       lstm_recognizer_ = new LSTMRecognizer(language_data_path_prefix.c_str());
       ASSERT_HOST(lstm_recognizer_->Load(this->params(), lstm_use_matrix ? language : "", mgr));
     } else {
+#ifdef DISABLED_LEGACY_ENGINE
+      // The legacy engine is compiled out, so we cannot fall back to it.
+      // Returning false here propagates a load failure to init_tesseract,
+      // which logs "Failed loading language '%s'" and skips this language.
+      tprintf(
+          "Error: LSTM requested, but not present in %s; the legacy "
+          "engine is disabled in this build, so there is no fallback.\n",
+          tessdata_path.c_str());
+      return false;
+#else
       tprintf("Error: LSTM requested, but not present!! Loading tesseract.\n");
       tessedit_ocr_engine_mode.set_value(OEM_TESSERACT_ONLY);
+#endif // DISABLED_LEGACY_ENGINE
     }
   }