From d1876900e53164bbd95118120706e360d0f01dd4 Mon Sep 17 00:00:00 2001
From: gwen <gwen@melvenn.(none)>
Date: Mon, 22 Feb 2016 17:37:24 +0100
Subject: [PATCH] correcting issue #4797

---
 hphp/runtime/base/execution-context.h                 |  2 +-
 hphp/runtime/base/unit-cache.cpp                      | 10 +++++-----
 hphp/runtime/debugger/debugger_hook_handler.cpp       |  2 +-
 hphp/runtime/ext/xdebug/hook.cpp                      |  2 +-
 hphp/test/slow/include/included_twice_different.php   | 11 +++++++++++
 .../slow/include/included_twice_different.php.expect  |  1 +
 6 files changed, 20 insertions(+), 8 deletions(-)
 create mode 100755 hphp/test/slow/include/included_twice_different.php
 create mode 100755 hphp/test/slow/include/included_twice_different.php.expect

diff --git a/hphp/runtime/base/execution-context.h b/hphp/runtime/base/execution-context.h
index 507c531bdc07f..2a79a07e29945 100644
--- a/hphp/runtime/base/execution-context.h
+++ b/hphp/runtime/base/execution-context.h
@@ -626,7 +626,7 @@ struct ExecutionContext {
   // destroying the context, so C++ order of destruction is not an issue.
   req::hash_map<const ObjectData*,ArrayNoDtor> dynPropTable;
   VarEnv* m_globalVarEnv;
-  req::hash_map<const StringData*,Unit*,string_data_hash,string_data_same>
+  req::hash_map<const StringData*,std::pair<Unit*,time_t>,string_data_hash,string_data_same>
     m_evaledFiles;
   req::vector<const StringData*> m_evaledFilesOrder;
   req::vector<Unit*> m_createdFuncs;
diff --git a/hphp/runtime/base/unit-cache.cpp b/hphp/runtime/base/unit-cache.cpp
index 9ae2e0b98ccc9..60b4a8496ab9c 100644
--- a/hphp/runtime/base/unit-cache.cpp
+++ b/hphp/runtime/base/unit-cache.cpp
@@ -483,9 +483,9 @@ Unit* lookupUnit(StringData* path, const char* currentDir, bool* initial_opt) {
 
   // Check if this file has already been included.
   auto it = eContext->m_evaledFiles.find(spath.get());
-  if (it != end(eContext->m_evaledFiles)) {
-    initial = false;
-    return it->second;
+  if (it != end(eContext->m_evaledFiles) && it->second.second >= s.st_mtime) {
+        initial = false;
+        return it->second.first;
   }
 
   // This file hasn't been included yet, so we need to parse the file
@@ -499,10 +499,10 @@ Unit* lookupUnit(StringData* path, const char* currentDir, bool* initial_opt) {
     // if parsing was successful, update the mappings for spath and
     // rpath (if it exists).
     eContext->m_evaledFilesOrder.push_back(cunit.unit->filepath());
-    eContext->m_evaledFiles[spath.get()] = cunit.unit;
+    eContext->m_evaledFiles[spath.get()] =  std::make_pair(cunit.unit,time(NULL));
     spath.get()->incRefCount();
     if (!cunit.unit->filepath()->same(spath.get())) {
-      eContext->m_evaledFiles[cunit.unit->filepath()] = cunit.unit;
+      eContext->m_evaledFiles[cunit.unit->filepath()] = std::make_pair(cunit.unit,time(NULL));
     }
     if (g_system_profiler) {
       g_system_profiler->fileLoadCallBack(path->toCppString());
diff --git a/hphp/runtime/debugger/debugger_hook_handler.cpp b/hphp/runtime/debugger/debugger_hook_handler.cpp
index 447767220cfd3..06a51bd240e0a 100644
--- a/hphp/runtime/debugger/debugger_hook_handler.cpp
+++ b/hphp/runtime/debugger/debugger_hook_handler.cpp
@@ -77,7 +77,7 @@ void proxySetBreakPoints(DebuggerProxy* proxy) {
     auto fileName = bp->m_file;
     if (!fileName.empty()) {
       for (auto& kv : g_context->m_evaledFiles) {
-        auto const unit = kv.second;
+        auto const unit = kv.second.first;
         if (!BreakPointInfo::MatchFile(fileName,
                             unit->filepath()->toCppString())) {
           continue;
diff --git a/hphp/runtime/ext/xdebug/hook.cpp b/hphp/runtime/ext/xdebug/hook.cpp
index 5ece9ce1aaff7..bc310ed51d84c 100644
--- a/hphp/runtime/ext/xdebug/hook.cpp
+++ b/hphp/runtime/ext/xdebug/hook.cpp
@@ -110,7 +110,7 @@ static const Unit* find_unit(String filename) {
   // Search the given filename in the list of evaled files. We translate each
   // unit's filename to a canonical format, which is slow, but necessary.
   for (auto& kv : g_context->m_evaledFiles) {
-    auto const unit = kv.second;
+    auto const unit = kv.second.first;
     String ufilename(const_cast<StringData*>(unit->filepath()));
     if (filename == File::TranslatePath(ufilename)) {
       return unit;
diff --git a/hphp/test/slow/include/included_twice_different.php b/hphp/test/slow/include/included_twice_different.php
new file mode 100755
index 0000000000000..c689ed6df6d36
--- /dev/null
+++ b/hphp/test/slow/include/included_twice_different.php
@@ -0,0 +1,11 @@
+<?php
+
+file_put_contents('foo.php', "<?php \n\$i=1;\n");
+include 'foo.php';
+echo $i;
+sleep(2); // just to make sure that timestamp is different 
+file_put_contents('foo.php', "<?php \n\$i=2;\n");
+include 'foo.php';
+echo $i;
+
+?>
diff --git a/hphp/test/slow/include/included_twice_different.php.expect b/hphp/test/slow/include/included_twice_different.php.expect
new file mode 100755
index 0000000000000..48082f72f087c
--- /dev/null
+++ b/hphp/test/slow/include/included_twice_different.php.expect
@@ -0,0 +1 @@
+12