Automatically add help index from /usr/share/doc/fpc/fpctoc.htx if it exists

diff --git a/fpcbuild/fpcsrc/packages/ide/fpini.pas b/fpcbuild/fpcsrc/ide/fpini.pas
index f911683..0449acc 100644
--- a/fpcbuild/fpcsrc/packages/ide/fpini.pas
+++ b/fpcbuild/fpcsrc/packages/ide/fpini.pas
@@ -455,6 +455,8 @@ begin
     end;
   { Help }
   S:=INIFile^.GetEntry(secHelp,ieHelpFiles,'');
+  if (S='') and (ExistsFile('/usr/share/doc/fpc/fpctoc.htx')) then
+    S:='/usr/share/doc/fpc/fpctoc.htx|Free Pascal Documentation';
   repeat
     P:=Pos(';',S); if P=0 then P:=length(S)+1;
     PS:=copy(S,1,P-1);
@@ -572,6 +574,11 @@ begin
   { Misc }
   ShowReadme:=INIFile^.GetIntEntry(secMisc,ieShowReadme,{integer(ShowReadme)}1)<>0;
   Dispose(INIFile, Done);
+ end
+ else
+ begin
+  if ExistsFile('/usr/share/doc/fpc/fpctoc.htx') then
+    HelpFiles^.Insert(NewStr('/usr/share/doc/fpc/fpctoc.htx|Free Pascal Documentation'));
  end;
   ReadINIFile:=OK;
 end;