Fixed bug 75709 "expires header not honored, gets cached copy"

r=gordon, sr=dougt, a=asa

netwerk/protocol/http/src/nsHttpChannel.cpp

@@ -746,6 +746,20 @@ nsHttpChannel::CheckCache()
         goto end;
     }
 
+    // Compare the Expires header to the Date header.  If the server sent an
+    // Expires header with a timestamp in the past, then we must validate this
+    // cached response before reusing.
+    {
+        PRUint32 expiresVal, dateVal;
+        if (NS_SUCCEEDED(mCachedResponseHead->GetExpiresValue(&expiresVal)) &&
+            NS_SUCCEEDED(mCachedResponseHead->GetDateValue(&dateVal)) &&
+            expiresVal < dateVal) {
+            LOG(("Validating since Expires < Date\n"));
+            doValidation = PR_TRUE;
+            goto end;
+        }
+    }
+
     // Check the Vary header.  Per comments on bug 37609, most of the request
     // headers that we generate do not vary with the exception of Accept-Charset
     // and Accept-Language, so we force validation only if these headers or "*"

netwerk/protocol/http/src/nsHttpResponseHead.h

@@ -81,10 +81,6 @@ public:
     // reset the response head to it's initial state
     void     Reset();
 
-private:
-    void     ParseVersion(const char *);
-    nsresult ParseContentType(char *);
-
     // these return failure if the header does not exist.
     nsresult ParseDateHeader(nsHttpAtom header, PRUint32 *result);
     nsresult GetAgeValue(PRUint32 *result);
@@ -93,6 +89,10 @@ private:
     nsresult GetExpiresValue(PRUint32 *result)      { return ParseDateHeader(nsHttp::Expires, result); }
     nsresult GetLastModifiedValue(PRUint32 *result) { return ParseDateHeader(nsHttp::Last_Modified, result); }
 
+private:
+    void     ParseVersion(const char *);
+    nsresult ParseContentType(char *);
+
 private:
     nsHttpHeaderArray mHeaders;
     nsHttpVersion     mVersion;