From 8aa3668731bd15e129ad5fc5abd41eba76bee838 Mon Sep 17 00:00:00 2001
From: m-kro <m.barthauer@t-online.de>
Date: Mon, 16 Oct 2023 11:08:46 +0200
Subject: [PATCH] remember BOM when reading file to set pos correctly ref
 #13932

Signed-off-by: m-kro <m.barthauer@t-online.de>
---
 src/utils/importio/LineReader.cpp | 9 ++++++---
 src/utils/importio/LineReader.h   | 2 ++
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/utils/importio/LineReader.cpp b/src/utils/importio/LineReader.cpp
index f3b1d86d131..7d96f0c1b71 100644
--- a/src/utils/importio/LineReader.cpp
+++ b/src/utils/importio/LineReader.cpp
@@ -15,6 +15,7 @@
 /// @author  Daniel Krajzewicz
 /// @author  Laura Bieker
 /// @author  Michael Behrisch
+/// @author  Mirko Barthauer
 /// @date    Fri, 19 Jul 2002
 ///
 // Retrieves a file linewise and reports the lines to a handler.
@@ -119,7 +120,7 @@ std::string
 LineReader::readLine() {
     std::string toReport;
     while (toReport.length() == 0 && myStrm.good()) {
-        const std::string::size_type idx = myStrBuffer.find('\n');
+        const std::string::size_type idx = myStrBuffer.find('\n');       
         if (idx == 0) {
             myStrBuffer = myStrBuffer.substr(1);
             myRread++;
@@ -137,6 +138,7 @@ LineReader::readLine() {
                             ? myAvailable - myRead
                             : 1024);
                 int noBytes = myAvailable - myRead;
+                bool bomAtStart = myBuffer[0] == '\xef' && myBuffer[1] == '\xbb' && myBuffer[2] == '\xbf';
                 noBytes = noBytes > 1024 ? 1024 : noBytes;
                 myStrBuffer += std::string(myBuffer, noBytes);
                 myRead += 1024;
@@ -204,7 +206,8 @@ LineReader::reinit() {
         // check for BOM
         myStrm.read(myBuffer, 3);
         if (myBuffer[0] == '\xef' && myBuffer[1] == '\xbb' && myBuffer[2] == '\xbf') {
-            myAvailable -= 3;
+            mySkipBOM = 3;
+            myAvailable -= mySkipBOM;
         } else {
             myStrm.seekg(0, std::ios::beg);
         }
@@ -218,7 +221,7 @@ LineReader::reinit() {
 
 void
 LineReader::setPos(unsigned long pos) {
-    myStrm.seekg(pos, std::ios::beg);
+    myStrm.seekg(pos + mySkipBOM, std::ios::beg);
     myRead = pos;
     myRread = pos;
     myStrBuffer = "";
diff --git a/src/utils/importio/LineReader.h b/src/utils/importio/LineReader.h
index 4327c555f83..afa509aad41 100644
--- a/src/utils/importio/LineReader.h
+++ b/src/utils/importio/LineReader.h
@@ -169,4 +169,6 @@ class LineReader {
     /// @brief Information how many lines were read for meaningful error messages
     int myLinesRead;
 
+    /// @brief Number of skipped characters at the file begin (UTF-8 BOM)
+    int mySkipBOM;
 };