3 files changed, 48 insertions, 7 deletions
diff --git a/webkit/data/plugins/force_reload.html b/webkit/data/plugins/force_reload.html
new file mode 100644
index 0000000..cc7cf39
--- /dev/null
+++ b/webkit/data/plugins/force_reload.html
@@ -0,0 +1,13 @@
+<html>
+<body>
+<embed id='1' type='application/vnd.npapi-test' src='foo' name='reload1'></embed>
+<script language="JavaScript">
+// Remove the existing embed object to force unload.
+var e = document.getElementById('1');
+e.parentNode.removeChild(e);
+
+// Add a new embed object to force reload.
+document.write("<embed id='2' type='application/vnd.npapi-test' src='foo' name='reload2'></embed>");
+</script>
+</body>
+</html>
diff --git a/webkit/glue/plugins/plugin_lib.cc b/webkit/glue/plugins/plugin_lib.cc
index ee613c1..292cd63 100644
--- a/webkit/glue/plugins/plugin_lib.cc
+++ b/webkit/glue/plugins/plugin_lib.cc
@@ -235,25 +235,41 @@ bool PluginLib::Load() {
 // This class implements delayed NP_Shutdown and FreeLibrary on the plugin dll.
 class FreePluginLibraryTask : public Task {
  public:
-  FreePluginLibraryTask(base::NativeLibrary library,
+  FreePluginLibraryTask(const FilePath& path,
+                        base::NativeLibrary library,
                         NP_ShutdownFunc shutdown_func)
-      : library_(library),
+      : path_(path),
+        library_(library),
         NP_Shutdown_(shutdown_func) {
   }
 
   ~FreePluginLibraryTask() {}
 
   void Run() {
-    if (NP_Shutdown_)
-      NP_Shutdown_();
+    if (NP_Shutdown_) {
+      // Don't call NP_Shutdown if the library has been reloaded since this task
+      // was posted.
+      bool reloaded = false;
+      if (g_loaded_libs) {
+        for (size_t i = 0; i < g_loaded_libs->size(); ++i) {
+          if ((*g_loaded_libs)[i]->plugin_info().path == path_)
+            reloaded = true;
+        }
+      }
+      if (!reloaded)
+        NP_Shutdown_();
+    }
 
     if (library_) {
+      // Always call base::UnloadNativeLibrary so that the system reference
+      // count is decremented.
       base::UnloadNativeLibrary(library_);
       library_ = NULL;
     }
   }
 
  private:
+  FilePath path_;
   base::NativeLibrary library_;
   NP_ShutdownFunc NP_Shutdown_;
   DISALLOW_COPY_AND_ASSIGN(FreePluginLibraryTask);
@@ -277,7 +293,8 @@ void PluginLib::Unload() {
 
     if (defer_unload) {
       FreePluginLibraryTask* free_library_task =
-          new FreePluginLibraryTask(skip_unload_ ? NULL : library_,
+          new FreePluginLibraryTask(web_plugin_info_.path,
+                                    skip_unload_ ? NULL : library_,
                                     entry_points_.np_shutdown);
       LOG_IF(ERROR, PluginList::DebugPluginLoading())
           << "Scheduling delayed unload for plugin "
diff --git a/webkit/tools/test_shell/plugin_tests.cc b/webkit/tools/test_shell/plugin_tests.cc
index ef1d8f0..ffb84bd 100644
--- a/webkit/tools/test_shell/plugin_tests.cc
+++ b/webkit/tools/test_shell/plugin_tests.cc
@@ -127,7 +127,7 @@ TEST_F(PluginTest, Refresh) {
 // don't crash.
 TEST_F(PluginTest, DeleteFrameDuringEvent) {
   FilePath test_html = data_dir_;
-  test_html = test_html.AppendASCII("plugins");
+  test_html = test_html.AppendASCII(TEST_PLUGIN_DIRECTORY);
   test_html = test_html.AppendASCII("delete_frame.html");
   test_shell_->LoadFile(test_html);
   test_shell_->WaitTestFinished();
@@ -142,6 +142,17 @@ TEST_F(PluginTest, DeleteFrameDuringEvent) {
   // No crash means we passed.
 }
 
+// Tests that a forced reload of the plugin will not crash.
+TEST_F(PluginTest, ForceReload) {
+  FilePath test_html = data_dir_;
+  test_html = test_html.AppendASCII(TEST_PLUGIN_DIRECTORY);
+  test_html = test_html.AppendASCII("force_reload.html");
+  test_shell_->LoadFile(test_html);
+  test_shell_->WaitTestFinished();
+
+  // No crash means we passed.
+}
+
 #if defined(OS_WIN)
 BOOL CALLBACK EnumChildProc(HWND hwnd, LPARAM lparam) {
   HWND* plugin_hwnd = reinterpret_cast<HWND*>(lparam);
@@ -157,7 +168,7 @@ BOOL CALLBACK EnumChildProc(HWND hwnd, LPARAM lparam) {
 // Tests that hiding/showing the parent frame hides/shows the plugin.
 TEST_F(PluginTest, PluginVisibilty) {
   FilePath test_html = data_dir_;
-  test_html = test_html.AppendASCII("plugins");
+  test_html = test_html.AppendASCII(TEST_PLUGIN_DIRECTORY);
   test_html = test_html.AppendASCII("plugin_visibility.html");
   test_shell_->LoadFile(test_html);
   test_shell_->WaitTestFinished();