try and except bug in inno setup - inno-setup

Question

In my code I wish to send http request and present it in fiddler - WinHttpReq.SetProxy(2, '127.0.0.1:8888'); if fiddle is up,
if fiddler is down dost esnd it to fiddler , I tried try..except this way:
[Setup] AppName=Test AppVersion=1.5 DefaultDirName={pf}\test
[Code]
var
WinHttpReq: Variant;
function ShowInFiddler(Param: String): String;
begin
try
WinHttpReq.SetProxy(2, '127.0.0.1:8888');
except MsgBox('Hello.', mbInformation, MB_OK);
end;
end;
function InitializeSetup(): Boolean;
begin
WinHttpReq := CreateOleObject('WinHttp.WinHttpRequest.5.1');
WinHttpReq.Open('GET', 'http://publishers-xxxx.databssint.com/', false);
ShowInFiddler ('');
WinHttpReq.Send(); end;
but the exception doesn't work, can anybody help?

Answer 1

This isn't a bug in Inno Setup, because the SetProxy function doesn't check if the proxy is availible. The function will raise an exception if you call it with wrong parameters.
So if your proxy is down you should catch the exception of the Send function and e.g. use the default proxy settings to continue.
For example:
var
WinHttpReq: Variant;
function InitializeSetup(): Boolean;
begin
WinHttpReq := CreateOleObject('WinHttp.WinHttpRequest.5.1');
WinHttpReq.Open('GET', 'http://publishers-xxxx.databssint.com/', false);
WinHttpReq.SetProxy(2, '127.0.0.1:8888');
try
// first try connecting via given proxy
WinHttpReq.Send();
except
// proxy failed, use default settings
WinHttpReq.SetProxy(0);
try
WinHttpReq.Send();
Result := true;
except
// conncetion failed, handle error here
ShowExceptionMessage();
end;
end;
end;
Keep in mind, that the debugger will paused by default on an exception (proxy is down). This will not happen in runtime.
Hope it helps.