From dd0a4014b68f9bb64910e915f40dc47ad14c0d24 Mon Sep 17 00:00:00 2001
From: juha <juha@lazarus-ide.org>
Date: Sun, 29 Dec 2019 23:18:57 +0000
Subject: [PATCH] LazUtils: LConvEncoding fix for CP936 and other DBCS
 codepages. Issue #36492, patch from CudaText man.

git-svn-id: trunk@62467 -
---
 .../lazutils/asiancodepagefunctions.inc       | 29 +++++++++++++++++--
 components/lazutils/lconvencoding.pas         | 25 ++++++++++++++--
 2 files changed, 49 insertions(+), 5 deletions(-)

diff --git a/components/lazutils/asiancodepagefunctions.inc b/components/lazutils/asiancodepagefunctions.inc
index 93e0f97c81..0bf5e8d55d 100644
--- a/components/lazutils/asiancodepagefunctions.inc
+++ b/components/lazutils/asiancodepagefunctions.inc
@@ -46,6 +46,20 @@ begin
       begin
         l:=UnicodeToUTF8Inline(code,Dest);
         inc(Dest,l);
+      end
+      else
+      case ConvertEncodingErrorMode of
+        ceemSkip:
+          begin end;
+        ceemException:
+          raise EConvertError.Create('Cannot convert DBCS code page to UTF8');
+        ceemReplace:
+          begin
+            Dest^:='?';
+            Inc(Dest);
+          end;
+        ceemReturmEmpty:
+          Exit('');
       end;
     end;
   until false;
@@ -209,8 +223,19 @@ begin
         Inc(Dest);
       end
       else
-      if ConvertEncodingFromUtf8RaisesException then
-        raise EConvertError.Create('Cannot convert UTF8 to DBCS code page');
+      case ConvertEncodingErrorMode of
+        ceemSkip:
+          begin end;
+        ceemException:
+          raise EConvertError.Create('Cannot convert UTF8 to DBCS code page');
+        ceemReplace:
+          begin
+            Dest^ := '?';
+            Inc(Dest);
+          end;
+        ceemReturmEmpty:
+          Exit('');
+      end;
     end;
   until false;
   //SetLength(Result, Dest - PChar(Result));
diff --git a/components/lazutils/lconvencoding.pas b/components/lazutils/lconvencoding.pas
index b8456e43ef..581e1637f2 100644
--- a/components/lazutils/lconvencoding.pas
+++ b/components/lazutils/lconvencoding.pas
@@ -31,8 +31,16 @@ uses
   SysUtils, Classes, dos, LazUTF8
   {$IFDEF EnableIconvEnc},iconvenc{$ENDIF};
 
+type
+  TConvertEncodingErrorMode = (
+    ceemSkip,
+    ceemException,
+    ceemReplace,
+    ceemReturmEmpty
+    );
+
 var
-  ConvertEncodingFromUtf8RaisesException: boolean = False;
+  ConvertEncodingErrorMode: TConvertEncodingErrorMode = ceemSkip;
 
 //encoding names
 const
@@ -2105,8 +2113,19 @@ begin
         inc(Dest);
       end
       else
-      if ConvertEncodingFromUtf8RaisesException then
-        raise EConvertError.Create('Cannot convert UTF8 to single byte');
+      case ConvertEncodingErrorMode of
+        ceemSkip:
+          begin end;
+        ceemException:
+          raise EConvertError.Create('Cannot convert UTF8 to single byte');
+        ceemReplace:
+          begin
+            Dest^:='?';
+            inc(Dest);
+          end;
+        ceemReturmEmpty:
+          Exit('');
+      end;
     end;
   end;
   SetLength(Result,Dest-PChar(Result));