Fix Installer VC Redist

Fixes #84

Author: Antoine Aflalo

Installer/scripts/products/vcredist2015.iss

@@ -16,18 +16,13 @@ de.vcredist2015_size_x64=13,9 MB
 const
 	vcredist2015_url = 'http://download.microsoft.com/download/C/E/5/CE514EAE-78A8-4381-86E8-29108D78DBD4/VC_redist.x86.exe';
 	vcredist2015_url_x64 = 'http://download.microsoft.com/download/C/E/5/CE514EAE-78A8-4381-86E8-29108D78DBD4/VC_redist.x64.exe';
-
-	vcredist2015_productcode = '{74D0E5DB-B326-4DAE-A6B2-445B9DE1836E}';
-	vcredist2015_productcode_x64 = '{0D3E9E15-DE7A-300B-96F1-B4AF12B96488}';
-
-  vcredist2015_productcode2 = '{65AD78AD-D23D-3A1E-9305-3AE65CD522C2}';
-	vcredist2015_productcode2_x64 = '{A1C31BA5-5438-3A07-9EEE-A5FB2D0FDE36}';
+  vc_redist_version = '14.0';
+  vc_redist_build = 23506;
 
 procedure vcredist2015();
 begin
 	if (not IsIA64()) then begin
-		if (not msiproduct(GetString(vcredist2015_productcode, vcredist2015_productcode_x64, '')) and 
-        not msiproduct(GetString(vcredist2015_productcode2, vcredist2015_productcode2_x64, ''))) then
+		if (not IsVcRedistInstalled(vc_redist_version, vc_redist_build)) then
 			AddProduct('vcredist2015' + GetArchitectureString() + '.exe',
 				'/passive /norestart',
 				CustomMessage('vcredist2015_title' + GetArchitectureString()),

Installer/scripts/products/vcredistversion.iss

@@ -0,0 +1,22 @@
+[Code]
+
+
+function IsVcRedistInstalled(version: String; build: Integer): boolean;
+var
+  regBuildNumber: cardinal;
+  regKey: String;
+  regInstalled: cardinal;
+begin
+  if(IsX64()) then begin
+    regKey := 'SOFTWARE\WOW6432Node\Microsoft\VisualStudio\'+ version +'\VC\Runtimes\x64';
+  end else begin
+    regKey := 'SOFTWARE\Microsoft\VisualStudio\'+ version +'\VC\VCRedist\x86';
+  end;
+  RegQueryDWordValue(HKLM, regKey, 'Installed', regInstalled);
+  if(regInstalled <> 1) then begin
+    Result := false
+    Exit;
+  end;
+  RegQueryDWordValue(HKLM, regKey, 'Bld', regBuildNumber);
+  Result := (regBuildNumber >= build);    
+end;

Installer/setup.iss

@@ -108,6 +108,7 @@ end;
 #include "scripts\products\winversion.iss"
 #include "scripts\products\fileversion.iss"
 #include "scripts\products\dotnetfxversion.iss"
+#include "scripts\products\vcredistversion.iss"
 
 // actual products
 #ifdef use_iis