Check if proxy values exists before reading from registry

[fabioxgn]

This ERegistryException is handled but it shows up in our logs, also it is not a good idea to use exceptions flow control.

[ronaldhoek]

I would ajust you're code some bit!

• when function 'if Reg.ValueExists(Value) then' return fails, please return a default value
• optionally change the the interface of 'ReadStringRegistryValue' and 'ReadIntegerRegistryValue' to be able to specifiy the default value as an optional parameter en remove the 'except' al together!

function ReadStringRegistryValue(const Value: string; const Default: string = ''): string;
var
  Reg: TRegistry;
begin
  Reg := TRegistry.Create;
  try
    Reg.RootKey := HKEY_CURRENT_USER;
    if Reg.OpenKey(INTERNET_SETTINGS, false) and
       Reg.ValueExists(Value) then
      Result := Reg.ReadString(Value)
    else
      Result := Default;
  finally
    Reg.Free;
  end;
end;

function ReadIntegerRegistryValue(const Value: string; const Default: Integer = 0): Integer;
var
  Reg: TRegistry;
begin
  Reg := TRegistry.Create;
  try
    Reg.RootKey := HKEY_CURRENT_USER;
    if Reg.OpenKey(INTERNET_SETTINGS, false) and
       Reg.ValueExists(Value) then
      Result := Reg.ReadInteger(Value)
    else
      Result := Default;
  finally
    Reg.Free;
  end;
end;

[fabioxgn]

@ronaldhoek did some changes to remove the exception handling using OpenKeyReadOnly. Also both functions already return a default, empty string or 0 and as it is used just in this unit, this is enough IMO.

[ronaldhoek]

@fabioxgn You're right, no need for the defaults!