Fix autotest failures in QAbstractNetworkCache

The cache expiration calculation was previously removed to avoid
calculating it every time an object is fetched from the cache.
This is because the expiration date is calculated from max-age or
expires headers when the object is added to the cache.

However this broke the case where the server only provides a
last-modified header. In this case, the expiration date needs
to be checked at fetch time in order to add the warning if the
object is >24h old.

Change-Id: Iad381da0f91c27ac603abbaa94f268700ad2297f
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 60 insertions, 58 deletions

diff --git a/src/network/access/qnetworkreplyhttpimpl.cpp b/src/network/access/qnetworkreplyhttpimpl.cpp
index a914ee3f04..101e1aa222 100644
--- a/src/network/access/qnetworkreplyhttpimpl.cpp
+++ b/src/network/access/qnetworkreplyhttpimpl.cpp
@@ -513,69 +513,71 @@ bool QNetworkReplyHttpImplPrivate::loadFromCacheIfAllowed(QHttpNetworkRequest &h
     QDateTime currentDateTime = QDateTime::currentDateTime();
     QDateTime expirationDate = metaData.expirationDate();
 
-#if 0
-    /*
-     * age_value
-     *      is the value of Age: header received by the cache with
-     *              this response.
-     * date_value
-     *      is the value of the origin server's Date: header
-     * request_time
-     *      is the (local) time when the cache made the request
-     *              that resulted in this cached response
-     * response_time
-     *      is the (local) time when the cache received the
-     *              response
-     * now
-     *      is the current (local) time
-     */
-    int age_value = 0;
-    it = cacheHeaders.findRawHeader("age");
-    if (it != cacheHeaders.rawHeaders.constEnd())
-        age_value = it->second.toInt();
-
-    QDateTime dateHeader;
-    int date_value = 0;
-    it = cacheHeaders.findRawHeader("date");
-    if (it != cacheHeaders.rawHeaders.constEnd()) {
-        dateHeader = QNetworkHeadersPrivate::fromHttpDate(it->second);
-        date_value = dateHeader.toTime_t();
-    }
-
-    int now = currentDateTime.toUTC().toTime_t();
-    int request_time = now;
-    int response_time = now;
+    bool response_is_fresh;
+    if (!expirationDate.isValid()) {
+        /*
+         * age_value
+         *      is the value of Age: header received by the cache with
+         *              this response.
+         * date_value
+         *      is the value of the origin server's Date: header
+         * request_time
+         *      is the (local) time when the cache made the request
+         *              that resulted in this cached response
+         * response_time
+         *      is the (local) time when the cache received the
+         *              response
+         * now
+         *      is the current (local) time
+         */
+        int age_value = 0;
+        it = cacheHeaders.findRawHeader("age");
+        if (it != cacheHeaders.rawHeaders.constEnd())
+            age_value = it->second.toInt();
 
-    // Algorithm from RFC 2616 section 13.2.3
-    int apparent_age = qMax(0, response_time - date_value);
-    int corrected_received_age = qMax(apparent_age, age_value);
-    int response_delay = response_time - request_time;
-    int corrected_initial_age = corrected_received_age + response_delay;
-    int resident_time = now - response_time;
-    int current_age   = corrected_initial_age + resident_time;
+        QDateTime dateHeader;
+        int date_value = 0;
+        it = cacheHeaders.findRawHeader("date");
+        if (it != cacheHeaders.rawHeaders.constEnd()) {
+            dateHeader = QNetworkHeadersPrivate::fromHttpDate(it->second);
+            date_value = dateHeader.toTime_t();
+        }
 
-    // RFC 2616 13.2.4 Expiration Calculations
-    if (!expirationDate.isValid()) {
-        if (lastModified.isValid()) {
-            int diff = currentDateTime.secsTo(lastModified);
-            expirationDate = lastModified;
-            expirationDate.addSecs(diff / 10);
-            if (httpRequest.headerField("Warning").isEmpty()) {
-                QDateTime dt;
-                dt.setTime_t(current_age);
-                if (dt.daysTo(currentDateTime) > 1)
-                    httpRequest.setHeaderField("Warning", "113");
+        int now = currentDateTime.toUTC().toTime_t();
+        int request_time = now;
+        int response_time = now;
+
+        // Algorithm from RFC 2616 section 13.2.3
+        int apparent_age = qMax(0, response_time - date_value);
+        int corrected_received_age = qMax(apparent_age, age_value);
+        int response_delay = response_time - request_time;
+        int corrected_initial_age = corrected_received_age + response_delay;
+        int resident_time = now - response_time;
+        int current_age   = corrected_initial_age + resident_time;
+
+        // RFC 2616 13.2.4 Expiration Calculations
+        if (!expirationDate.isValid()) {
+            if (lastModified.isValid()) {
+                int diff = currentDateTime.secsTo(lastModified);
+                expirationDate = lastModified;
+                expirationDate.addSecs(diff / 10);
+                if (httpRequest.headerField("Warning").isEmpty()) {
+                    QDateTime dt;
+                    dt.setTime_t(current_age);
+                    if (dt.daysTo(currentDateTime) > 1)
+                        httpRequest.setHeaderField("Warning", "113");
+                }
             }
         }
-    }
 
-    // the cache-saving code below sets the expirationDate with date+max_age
-    // if "max-age" is present, or to Expires otherwise
-    int freshness_lifetime = dateHeader.secsTo(expirationDate);
-    bool response_is_fresh = (freshness_lifetime > current_age);
-#else
-    bool response_is_fresh = currentDateTime.secsTo(expirationDate) >= 0;
-#endif
+        // the cache-saving code below sets the expirationDate with date+max_age
+        // if "max-age" is present, or to Expires otherwise
+        int freshness_lifetime = dateHeader.secsTo(expirationDate);
+        response_is_fresh = (freshness_lifetime > current_age);
+    } else {
+        // expiration date was calculated earlier (e.g. when storing object to the cache)
+        response_is_fresh = currentDateTime.secsTo(expirationDate) >= 0;
+    }
 
     if (!response_is_fresh)
         return false;