From b0b8dfbc816b60f8e0a2872e2fb343c60a25989b Mon Sep 17 00:00:00 2001
From: Stefan Weil <sw@weilnetz.de>
Date: Thu, 18 Oct 2018 19:18:20 +0200
Subject: [PATCH 1/2] TessResultRenderer: Extend API to access status of
 renderer

Signed-off-by: Stefan Weil <sw@weilnetz.de>
---
 src/api/renderer.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/api/renderer.h b/src/api/renderer.h
index 55f1a2fa3..6c753403c 100644
--- a/src/api/renderer.h
+++ b/src/api/renderer.h
@@ -80,6 +80,9 @@ class TESS_API TessResultRenderer {
     const char* file_extension() const { return file_extension_; }
     const char* title() const { return title_.c_str(); }
 
+    // Is everything fine? Otherwise something went wrong.
+    bool happy() { return happy_; }
+
     /**
      * Returns the index of the last image given to AddImage
      * (i.e. images are incremented whether the image succeeded or not)

From 49d7df6dc3efc61861c783021e06567d3d4780f0 Mon Sep 17 00:00:00 2001
From: Stefan Weil <sw@weilnetz.de>
Date: Thu, 18 Oct 2018 19:22:13 +0200
Subject: [PATCH 2/2] tesseractmain: Show error message when output file could
 not be created

Signed-off-by: Stefan Weil <sw@weilnetz.de>
---
 src/api/tesseractmain.cpp | 61 ++++++++++++++++++++++++++++++++-------
 1 file changed, 51 insertions(+), 10 deletions(-)

diff --git a/src/api/tesseractmain.cpp b/src/api/tesseractmain.cpp
index d22f7d9a3..bcf156ffe 100644
--- a/src/api/tesseractmain.cpp
+++ b/src/api/tesseractmain.cpp
@@ -22,6 +22,7 @@
 #include "config_auto.h"
 #endif
 
+#include <cerrno>               // for errno
 #include <iostream>
 
 #include "allheaders.h"
@@ -33,7 +34,7 @@
 #include "renderer.h"
 #include "simddetect.h"
 #include "strngs.h"
-#include "tprintf.h"
+#include "tprintf.h"            // for tprintf
 
 #if defined(_WIN32)
 #include <fcntl.h>
@@ -407,16 +408,28 @@ static void PreloadRenderers(
     if (b) {
       bool font_info;
       api->GetBoolVariable("hocr_font_info", &font_info);
-      renderers->push_back(
-          new tesseract::TessHOcrRenderer(outputbase, font_info));
+      tesseract::TessHOcrRenderer* renderer =
+          new tesseract::TessHOcrRenderer(outputbase, font_info);
+      if (renderer->happy()) {
+        renderers->push_back(renderer);
+      } else {
+        tprintf("Error, could not create hOCR output file: %s\n",
+                strerror(errno));
+      }
     }
 
     api->GetBoolVariable("tessedit_create_tsv", &b);
     if (b) {
       bool font_info;
       api->GetBoolVariable("hocr_font_info", &font_info);
-      renderers->push_back(
-          new tesseract::TessTsvRenderer(outputbase, font_info));
+      tesseract::TessTsvRenderer* renderer =
+          new tesseract::TessTsvRenderer(outputbase, font_info);
+      if (renderer->happy()) {
+        renderers->push_back(renderer);
+      } else {
+        tprintf("Error, could not create TSV output file: %s\n",
+                strerror(errno));
+      }
     }
 
     api->GetBoolVariable("tessedit_create_pdf", &b);
@@ -427,23 +440,51 @@ static void PreloadRenderers(
       #endif  // WIN32
       bool textonly;
       api->GetBoolVariable("textonly_pdf", &textonly);
-      renderers->push_back(new tesseract::TessPDFRenderer(
-          outputbase, api->GetDatapath(), textonly));
+      tesseract::TessPDFRenderer* renderer =
+        new tesseract::TessPDFRenderer(outputbase, api->GetDatapath(),
+                                       textonly);
+      if (renderer->happy()) {
+        renderers->push_back(renderer);
+      } else {
+        tprintf("Error, could not create PDF output file: %s\n",
+                strerror(errno));
+      }
     }
 
     api->GetBoolVariable("tessedit_write_unlv", &b);
     if (b) {
-      renderers->push_back(new tesseract::TessUnlvRenderer(outputbase));
+      tesseract::TessUnlvRenderer* renderer =
+        new tesseract::TessUnlvRenderer(outputbase);
+      if (renderer->happy()) {
+        renderers->push_back(renderer);
+      } else {
+        tprintf("Error, could not create UNLV output file: %s\n",
+                strerror(errno));
+      }
     }
 
     api->GetBoolVariable("tessedit_create_boxfile", &b);
     if (b) {
-      renderers->push_back(new tesseract::TessBoxTextRenderer(outputbase));
+      tesseract::TessBoxTextRenderer* renderer =
+        new tesseract::TessBoxTextRenderer(outputbase);
+      if (renderer->happy()) {
+        renderers->push_back(renderer);
+      } else {
+        tprintf("Error, could not create BOX output file: %s\n",
+                strerror(errno));
+      }
     }
 
     api->GetBoolVariable("tessedit_create_txt", &b);
     if (b || renderers->empty()) {
-      renderers->push_back(new tesseract::TessTextRenderer(outputbase));
+      tesseract::TessTextRenderer* renderer =
+        new tesseract::TessTextRenderer(outputbase);
+      if (renderer->happy()) {
+        renderers->push_back(renderer);
+      } else {
+        tprintf("Error, could not create TXT output file: %s\n",
+                strerror(errno));
+      }
     }
   }