From fdc824ac5eb2fb47f7ca05d86bf5e04e41b63b28 Mon Sep 17 00:00:00 2001
From: kohsuke <kohsuke@71c3de6d-444a-0410-be80-ed276b4c234a>
Date: Sat, 12 Jan 2008 02:27:29 +0000
Subject: [PATCH] don't let the image be cached (#1167)

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@6593 71c3de6d-444a-0410-be80-ed276b4c234a
---
 core/src/main/java/hudson/security/SecurityRealm.java | 1 +
 1 file changed, 1 insertion(+)

diff --git a/core/src/main/java/hudson/security/SecurityRealm.java b/core/src/main/java/hudson/security/SecurityRealm.java
index e188b2a4ca..486c6a9743 100644
--- a/core/src/main/java/hudson/security/SecurityRealm.java
+++ b/core/src/main/java/hudson/security/SecurityRealm.java
@@ -120,6 +120,7 @@ public abstract class SecurityRealm implements Describable<SecurityRealm>, Exten
     public final void doCaptcha(StaplerRequest req, StaplerResponse rsp) throws IOException {
         String id = req.getSession().getId();
         rsp.setContentType("image/png");
+        rsp.addHeader("Cache-Control","no-cache");
         ImageIO.write( CaptchaService.INSTANCE.getImageChallengeForID(id), "PNG", rsp.getOutputStream() );
     }