Fix wrong font attributes in hOCR output

Instrumented code throws this runtime error during OCR:

    ../../src/api/baseapi.cpp:1616:5: runtime error: load of value 128,
      which is not a valid value for type 'bool'
    ../../src/api/baseapi.cpp:1627:5: runtime error: load of value 128,
      which is not a valid value for type 'bool'

If there is no font information (typical for Tesseract with a LSTM model),
the font attributes got random values resulting in wrong hOCR output.

Signed-off-by: Stefan Weil <sw@weilnetz.de>

src/ccmain/ltrresultiterator.cpp

@@ -171,27 +171,43 @@ const char* LTRResultIterator::WordFontAttributes(bool* is_bold,
                                                   bool* is_smallcaps,
                                                   int* pointsize,
                                                   int* font_id) const {
-  if (it_->word() == nullptr) return nullptr;  // Already at the end!
-  float row_height = it_->row()->row->x_height() +
-      it_->row()->row->ascenders() - it_->row()->row->descenders();
-  // Convert from pixels to printers points.
-  *pointsize = scaled_yres_ > 0
-      ? static_cast<int>(row_height * kPointsPerInch / scaled_yres_ + 0.5)
-      : 0;
-  if (it_->word()->fontinfo == nullptr) {
+  const char* result = nullptr;
+
+  if (it_->word()) {
+    // Already at the end!
+    *pointsize = 0;
+  } else {
+    float row_height = it_->row()->row->x_height() +
+        it_->row()->row->ascenders() - it_->row()->row->descenders();
+    // Convert from pixels to printers points.
+    *pointsize = scaled_yres_ > 0
+        ? static_cast<int>(row_height * kPointsPerInch / scaled_yres_ + 0.5)
+        : 0;
+    const FontInfo* font_info = it_->word()->fontinfo;
+    if (font_info) {
+      // Font information available.
+      *font_id = font_info->universal_id;
+      *is_bold = font_info->is_bold();
+      *is_italic = font_info->is_italic();
+      *is_underlined = false;  // TODO(rays) fix this!
+      *is_monospace = font_info->is_fixed_pitch();
+      *is_serif = font_info->is_serif();
+      *is_smallcaps = it_->word()->small_caps;
+      result = font_info->name;
+    }
+  }
+
+  if (!result) {
+    *is_bold = false;
+    *is_italic = false;
+    *is_underlined = false;
+    *is_monospace = false;
+    *is_serif = false;
+    *is_smallcaps = false;
     *font_id = -1;
-    return nullptr;  // No font information.
   }
-  const FontInfo& font_info = *it_->word()->fontinfo;
-  *font_id = font_info.universal_id;
-  *is_bold = font_info.is_bold();
-  *is_italic = font_info.is_italic();
-  *is_underlined = false;  // TODO(rays) fix this!
-  *is_monospace = font_info.is_fixed_pitch();
-  *is_serif = font_info.is_serif();
-  *is_smallcaps = it_->word()->small_caps;
-
-  return font_info.name;
+
+  return result;
 }
 
 // Returns the name of the language used to recognize this word.