Bundle python dll in win32 installer if present

in case hg.exe is generated with the py2exe '-b 2' option instead of '-b 1',
python2?.dll is not included in library.zip file and must also be packaged.
The file will be integrated in the installer only if it is present in the dist
directory.  Generating hg.exe with the '-b 2' option is mandatory to avoid a
crash when pyreadline is installed.

contrib/win32/mercurial.iss

@@ -1,100 +1,101 b''
 ; Script generated by the Inno Setup Script Wizard.
 ; SEE THE DOCUMENTATION FOR DETAILS ON CREATING INNO SETUP SCRIPT FILES!
 [Setup]
 AppCopyright=Copyright 2005-2009 Matt Mackall and others
 AppName=Mercurial
 AppVerName=Mercurial snapshot
 InfoAfterFile=contrib/win32/postinstall.txt
 LicenseFile=COPYING
 ShowLanguageDialog=yes
 AppPublisher=Matt Mackall and others
 AppPublisherURL=http://www.selenic.com/mercurial
 AppSupportURL=http://www.selenic.com/mercurial
 AppUpdatesURL=http://www.selenic.com/mercurial
 AppID={{4B95A5F1-EF59-4B08-BED8-C891C46121B3}
 AppContact=[e-mail]
 OutputBaseFilename=Mercurial-snapshot
 DefaultDirName={pf}\Mercurial
 SourceDir=..\..
 VersionInfoDescription=Mercurial distributed SCM
 VersionInfoCopyright=Copyright 2005-2009 Matt Mackall and others
 VersionInfoCompany=Matt Mackall and others
 InternalCompressLevel=max
 SolidCompression=true
 SetupIconFile=contrib\win32\mercurial.ico
 AllowNoIcons=true
 DefaultGroupName=Mercurial
 PrivilegesRequired=none
 
 [Files]
 Source: contrib\mercurial.el; DestDir: {app}/Contrib
 Source: contrib\vim\*.*; DestDir: {app}/Contrib/Vim
 Source: contrib\zsh_completion; DestDir: {app}/Contrib
 Source: contrib\hgk; DestDir: {app}/Contrib; DestName: hgk.tcl
 Source: contrib\win32\ReadMe.html; DestDir: {app}; Flags: isreadme
 Source: contrib\mergetools.hgrc; DestDir: {tmp};
 Source: contrib\win32\mercurial.ini; DestDir: {app}; DestName: Mercurial.ini; Check: CheckFile; AfterInstall: ConcatenateFiles;
 Source: contrib\win32\postinstall.txt; DestDir: {app}; DestName: ReleaseNotes.txt
 Source: dist\hg.exe; DestDir: {app}; AfterInstall: Touch('{app}\hg.exe.local')
+Source: dist\python*.dll; Destdir: {app}; Flags: skipifsourcedoesntexist
 Source: dist\library.zip; DestDir: {app}
 Source: dist\mfc71.dll; DestDir: {app}
 Source: dist\msvcr71.dll; DestDir: {app}
 Source: dist\w9xpopen.exe; DestDir: {app}
 Source: dist\add_path.exe; DestDir: {app}
 Source: doc\*.html; DestDir: {app}\Docs
 Source: locale\*.*; DestDir: {app}\locale; Flags: recursesubdirs createallsubdirs
 Source: templates\*.*; DestDir: {app}\Templates; Flags: recursesubdirs createallsubdirs
 Source: CONTRIBUTORS; DestDir: {app}; DestName: Contributors.txt
 Source: COPYING; DestDir: {app}; DestName: Copying.txt
 
 [INI]
 Filename: {app}\Mercurial.url; Section: InternetShortcut; Key: URL; String: http://www.selenic.com/mercurial/
 
 [UninstallDelete]
 Type: files; Name: {app}\Mercurial.url
 
 [Icons]
 Name: {group}\Uninstall Mercurial; Filename: {uninstallexe}
 Name: {group}\Mercurial Command Reference; Filename: {app}\Docs\hg.1.html
 Name: {group}\Mercurial Configuration Files; Filename: {app}\Docs\hgrc.5.html
 Name: {group}\Mercurial Ignore Files; Filename: {app}\Docs\hgignore.5.html
 Name: {group}\Mercurial Web Site; Filename: {app}\Mercurial.url
 
 [Run]
 Filename: "{app}\add_path.exe"; Parameters: "{app}"; Flags: postinstall; Description: "Add the installation path to the search path"
 
 [UninstallRun]
 Filename: "{app}\add_path.exe"; Parameters: "/del {app}"
 
 [UninstallDelete]
 Type: files; Name: "{app}\hg.exe.local"
 [Code]
 var
   WriteFile: Boolean;
   CheckDone: Boolean;
 
 function CheckFile(): Boolean;
 begin
   if not CheckDone then begin
     WriteFile := True;
     if FileExists(ExpandConstant(CurrentFileName)) then begin
         WriteFile := MsgBox('' + ExpandConstant(CurrentFileName) + '' #13#13 'The file already exists.' #13#13 'Would you like Setup to overwrite it?', mbConfirmation, MB_YESNO) = idYes;
     end;
     CheckDone := True;
   end;
   Result := WriteFile;
 end;
 
 procedure ConcatenateFiles();
 var
   MergeConfigs: TArrayOfString;
 begin
   if LoadStringsFromFile(ExpandConstant('{tmp}\mergetools.hgrc'),MergeConfigs) then begin
     SaveStringsToFile(ExpandConstant(CurrentFileName),MergeConfigs,True);
   end;
 end;
 
 procedure Touch(fn: String);
 begin
   SaveStringToFile(ExpandConstant(fn), '', False);
 end;