Don't set Last-Modified on IPRO Requests

Fixes #1106

net/instaweb/apache/apache_writer.cc

@@ -80,7 +80,6 @@ void ApacheWriter::OutputHeaders(ResponseHeaders* response_headers) {
   if (content_length_ != AsyncFetch::kContentLengthUnknown) {
     ap_set_content_length(request_, content_length_);
   }
-
   ResponseHeadersToApacheRequest(*response_headers, request_);
   request_->status = response_headers->status_code();
   if (disable_downstream_header_filters_) {

net/instaweb/apache/system_test.sh

@@ -128,8 +128,28 @@ if [ $statistics_logging_enabled = "1" ]; then
   sleep 2; # Make sure we're around long enough to log stats.
 fi
 
-# General system tests
+start_test ipro resources have etag and not last-modified
+URL="$EXAMPLE_ROOT/images/Puzzle.jpg?a=$RANDOM"
+# Fetch it a few times until IPRO is done and has given it an ipro ("aj") etag.
+fetch_until -save "$URL" 'grep -c E[Tt]ag:.W/.PSA-aj.' 1 --save-headers
+# Verify that it doesn't have a Last-Modified header.
+check [ $(grep -c "^Last-Modified:" $FETCH_FILE) = 0 ]
+# Extract the Etag and verify we get "not modified" when we send the it.
+ETAG=$(grep -a -o 'W/"PSA-aj[^"]*"' $FETCH_FILE)
+check_from "$ETAG" fgrep PSA
+echo $CURL -sS -D- -o/dev/null -H "If-None-Match: $ETAG" $URL
+OUT=$($CURL -sS -D- -o/dev/null -H "If-None-Match: $ETAG" $URL)
+check_from "$OUT" fgrep "HTTP/1.1 304"
+check_not_from "$OUT" fgrep "Content-Length"
+# Verify we don't get a 304 with a different Etag.
+BAD_ETAG=$(echo "$ETAG" | sed s/PSA-aj/PSA-ic/)
+echo $CURL -sS -D- -o/dev/null -H "If-None-Match: $BAD_ETAG" $URL
+OUT=$($CURL -sS -D- -o/dev/null -H "If-None-Match: $BAD_ETAG" $URL)
+check_not_from "$OUT" fgrep "HTTP/1.1 304"
+check_from "$OUT" fgrep "HTTP/1.1 200"
+check_from "$OUT" fgrep "Content-Length"
 
+# General system tests
 start_test Check for correct default X-Mod-Pagespeed header format.
 OUT=$($WGET_DUMP $EXAMPLE_ROOT/combine_css.html)
 check_from "$OUT" egrep -q \

net/instaweb/rewriter/in_place_rewrite_context.cc

@@ -389,6 +389,7 @@ void InPlaceRewriteContext::FixFetchFallbackHeaders(
       headers->Replace(HttpAttributes::kEtag, HTTPCache::FormatEtag(StrCat(
                                                   id(), "-", rewritten_hash_)));
     }
+    headers->RemoveAll(HttpAttributes::kLastModified);
     headers->set_implicit_cache_ttl_ms(Options()->implicit_cache_ttl_ms());
     headers->set_min_cache_ttl_ms(Options()->min_cache_ttl_ms());
     headers->ComputeCaching();

net/instaweb/system/admin_site.cc

@@ -103,13 +103,16 @@ const Tab kTabs[] = {
 class AdminHtml {
  public:
   AdminHtml(StringPiece current_link, StringPiece head_extra,
-            AdminSite::AdminSource source, AsyncFetch* fetch,
-            MessageHandler* handler)
+            AdminSite::AdminSource source, Timer* timer,
+            AsyncFetch* fetch, MessageHandler* handler)
       : fetch_(fetch),
         handler_(handler) {
     fetch->response_headers()->SetStatusAndReason(HttpStatus::kOK);
     fetch->response_headers()->Add(HttpAttributes::kContentType, "text/html");
 
+    int64 now_ms = timer->NowMs();
+    fetch->response_headers()->SetLastModified(now_ms);
+
     // Let PageSpeed dynamically minify the html, css, and javasript
     // generated by the admin page, to the extent it's not done
     // already by the tools.  Note, this does mean that viewing the
@@ -211,7 +214,7 @@ void AdminSite::ConsoleHandler(const SystemRewriteOptions& global_options,
   // TODO(sligocki): Do we want to have a minified version of console CSS?
   GoogleString head_markup = StrCat(
       "<style>", CSS_console_css, "</style>\n");
-  AdminHtml admin_html("console", head_markup, source, fetch,
+  AdminHtml admin_html("console", head_markup, source, timer_, fetch,
                        message_handler_);
   if (statistics_enabled && logging_enabled && log_dir_set) {
     fetch->Write("<div class='console_div' id='suggestions'>\n"
@@ -267,7 +270,7 @@ void AdminSite::StatisticsHandler(const RewriteOptions& options,
                                   Statistics* stats) {
   GoogleString head_markup = StrCat(
       "<style>", CSS_statistics_css, "</style>\n");
-  AdminHtml admin_html("statistics", head_markup, source, fetch,
+  AdminHtml admin_html("statistics", head_markup, source, timer_, fetch,
                        message_handler_);
   // We have to call Dump() here to write data to sources for
   // system/system_test.sh: Line 79. We use JS to update the data in refreshes.
@@ -293,7 +296,8 @@ void AdminSite::GraphsHandler(const RewriteOptions& options,
   }
   GoogleString head_markup = StrCat(
       "<style>", CSS_graphs_css, "</style>\n");
-  AdminHtml admin_html("graphs", head_markup, source, fetch, message_handler_);
+  AdminHtml admin_html("graphs", head_markup, source, timer_, fetch,
+                       message_handler_);
   fetch->Write("<div id='cache_applied'>Loading Charts...</div>"
                "<div id='cache_type'>Loading Charts...</div>"
                "<div id='ipro'>Loading Charts...</div>"
@@ -367,7 +371,8 @@ void AdminSite::ConsoleJsonHandler(const QueryParams& params,
 
 void AdminSite::PrintHistograms(AdminSource source, AsyncFetch* fetch,
                                 Statistics* stats) {
-  AdminHtml admin_html("histograms", "", source, fetch, message_handler_);
+  AdminHtml admin_html("histograms", "", source, timer_, fetch,
+                       message_handler_);
   stats->RenderHistograms(fetch, message_handler_);
 }
 
@@ -551,7 +556,7 @@ void AdminSite::PrintCaches(bool is_global, AdminSource source,
   } else {
     GoogleString head_markup = StrCat(
         "<style>", CSS_caches_css, "</style>\n");
-    AdminHtml admin_html("cache", head_markup, source, fetch,
+    AdminHtml admin_html("cache", head_markup, source, timer_, fetch,
                          message_handler_);
 
     fetch->Write("<div id='show_metadata'>", message_handler_);
@@ -624,15 +629,16 @@ void AdminSite::PrintCaches(bool is_global, AdminSource source,
 void AdminSite::PrintNormalConfig(
     AdminSource source, AsyncFetch* fetch,
     SystemRewriteOptions* global_system_rewrite_options) {
-  AdminHtml admin_html("config", "", source, fetch, message_handler_);
+  AdminHtml admin_html("config", "", source, timer_, fetch, message_handler_);
   HtmlKeywords::WritePre(
       global_system_rewrite_options->OptionsToString(), "",
       fetch, message_handler_);
 }
 
 void AdminSite::PrintSpdyConfig(AdminSource source, AsyncFetch* fetch,
                                 const SystemRewriteOptions* spdy_config) {
-  AdminHtml admin_html("spdy_config", "", source, fetch, message_handler_);
+  AdminHtml admin_html("spdy_config", "", source, timer_, fetch,
+                       message_handler_);
   if (spdy_config == NULL) {
     fetch->Write("SPDY-specific configuration missing.", message_handler_);
   } else {
@@ -646,7 +652,8 @@ void AdminSite::MessageHistoryHandler(const RewriteOptions& options,
   // Request for page /mod_pagespeed_message.
   GoogleString log;
   StringWriter log_writer(&log);
-  AdminHtml admin_html("message_history", "", source, fetch, message_handler_);
+  AdminHtml admin_html("message_history", "", source, timer_, fetch,
+                       message_handler_);
   if (message_handler_->Dump(&log_writer)) {
     fetch->Write("<div id='log'>", message_handler_);
     // Write pre-tag and color messages.

pagespeed/apache/apache_fetch.cc

@@ -87,7 +87,6 @@ void ApacheFetch::HandleHeadersComplete() {
 
     int64 now_ms = timer_->NowMs();
     response_headers()->SetDate(now_ms);
-    response_headers()->SetLastModified(now_ms);
 
     // http://msdn.microsoft.com/en-us/library/ie/gg622941(v=vs.85).aspx
     // Script and styleSheet elements will reject responses with

pagespeed/apache/apache_fetch_test.cc

@@ -213,7 +213,6 @@ TEST_F(ApacheFetchTest, Success) {
             "Set-Cookie: tasty=cookie\n"
             "Set-Cookie2: obselete\n"
             "Date: Thu, 01 Jan 1970 00:00:00 GMT\n"
-            "Last-Modified: Thu, 01 Jan 1970 00:00:00 GMT\n"
             "X-Content-Type-Options: nosniff\n"
             "Cache-Control: max-age=0, no-cache\n",
             HeadersOutToString(&request_));
@@ -239,7 +238,6 @@ TEST_F(ApacheFetchTest, NotFound404) {
             "Set-Cookie: tasty=cookie\n"
             "Set-Cookie2: obselete\n"
             "Date: Thu, 01 Jan 1970 00:00:00 GMT\n"
-            "Last-Modified: Thu, 01 Jan 1970 00:00:00 GMT\n"
             "X-Content-Type-Options: nosniff\n"
             "Cache-Control: max-age=0, no-cache\n",
             HeadersOutToString(&request_));
@@ -264,7 +262,6 @@ TEST_F(ApacheFetchTest, NoContentType200) {
             "Set-Cookie2: obselete\n"
             "Content-Type: text/html\n"
             "Date: Thu, 01 Jan 1970 00:00:00 GMT\n"
-            "Last-Modified: Thu, 01 Jan 1970 00:00:00 GMT\n"
             "X-Content-Type-Options: nosniff\n"
             "Cache-Control: max-age=0, no-cache\n",
             HeadersOutToString(&request_));
@@ -290,7 +287,6 @@ TEST_F(ApacheFetchTest, NoContentType301) {
             "Location: elsewhere\n"
             "Content-Type: text/html\n"
             "Date: Thu, 01 Jan 1970 00:00:00 GMT\n"
-            "Last-Modified: Thu, 01 Jan 1970 00:00:00 GMT\n"
             "X-Content-Type-Options: nosniff\n"
             "Cache-Control: max-age=0, no-cache\n",
             HeadersOutToString(&request_));
@@ -313,7 +309,6 @@ TEST_F(ApacheFetchTest, NoContentType304) {
             "Set-Cookie: tasty=cookie\n"
             "Set-Cookie2: obselete\n"
             "Date: Thu, 01 Jan 1970 00:00:00 GMT\n"
-            "Last-Modified: Thu, 01 Jan 1970 00:00:00 GMT\n"
             "X-Content-Type-Options: nosniff\n"
             "Cache-Control: max-age=0, no-cache\n",
             HeadersOutToString(&request_));
@@ -334,7 +329,6 @@ TEST_F(ApacheFetchTest, NoContentType204) {
             "Set-Cookie: tasty=cookie\n"
             "Set-Cookie2: obselete\n"
             "Date: Thu, 01 Jan 1970 00:00:00 GMT\n"
-            "Last-Modified: Thu, 01 Jan 1970 00:00:00 GMT\n"
             "X-Content-Type-Options: nosniff\n"
             "Cache-Control: max-age=0, no-cache\n",
             HeadersOutToString(&request_));
@@ -361,7 +355,6 @@ TEST_F(ApacheFetchTest, AbandonedAndHandled) {
             "Set-Cookie: tasty=cookie\n"
             "Set-Cookie2: obselete\n"
             "Date: Thu, 01 Jan 1970 00:00:00 GMT\n"
-            "Last-Modified: Thu, 01 Jan 1970 00:00:00 GMT\n"
             "X-Content-Type-Options: nosniff\n"
             "Cache-Control: max-age=0, no-cache\n",
             HeadersOutToString(&request_));