From 840389dad3b79d180297422d7c208950f4ecdc4e Mon Sep 17 00:00:00 2001
From: Bart <9132501-flyingsheep@users.noreply.gitlab.com>
Date: Fri, 20 Aug 2021 18:43:19 +0200
Subject: [PATCH] LazFileUtils: make ResolveDots a little more consitent w.r.t.
 having the result ending with a PathDelim. Issue #37188. Do not merge to
 Fixes 2.2.

---
 components/lazutils/lazfileutils.inc | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/components/lazutils/lazfileutils.inc b/components/lazutils/lazfileutils.inc
index 698fe69fe1..d7471823fe 100644
--- a/components/lazutils/lazfileutils.inc
+++ b/components/lazutils/lazfileutils.inc
@@ -24,6 +24,7 @@ function ResolveDots(const AFilename: string): string;
 var SrcPos, DestPos, Len, DirStart: integer;
   c: char;
   MacroPos: LongInt;
+  ResultMustEndWithPathDelim: Boolean;
 begin
   Len:=length(AFilename);
   if Len=0 then exit('');
@@ -37,6 +38,13 @@ begin
     exit;
   {$endif}
 
+  //To add some consistency to the outcomes
+  //Depending on the path the algorithm takes it may remove the trailing PathDelim, so we restore it later if needed
+  //Issue #37188
+  //It's a workaround, fee free to implement a better fix
+  ResultMustEndWithPathDelim := ((Len>2) and (AFilename[Len]='.') and (AFilename[Len-1]='.') and (AFilename[Len-2] in AllowDirectorySeparators)) or
+                                ((Len>1) and (AFilename[Len]='.') and (AFilename[Len-1] in AllowDirectorySeparators));
+
   SrcPos:=1;
   DestPos:=1;
 
@@ -169,7 +177,7 @@ begin
           // foo/. -> foo
           // C:foo\. -> C:foo
           // C:\. -> C:\
-          dec(DestPos);
+          {dec(DestPos); } //Part of issue #37188
         end;
         break;
       end;
@@ -194,6 +202,8 @@ begin
       Result:='.'
     else
       SetLength(Result,DestPos-1);
+  if ResultMustEndWithPathDelim and (Result<>'.') and (Result[Length(Result)]<>PathDelim) then
+    Result := Result + PathDelim;
 end;
 
 function FilenameIsWinAbsolute(const TheFilename: string): boolean;