mshtml: Don't do anything in exec_editmode if edit mode is already set.

dlls/mshtml/olecmd.c

@@ -523,6 +523,9 @@ static HRESULT exec_editmode(HTMLDocument *This, DWORD cmdexecopt, VARIANT *in,
     if(in || out)
         FIXME("unsupported args\n");
 
+    if(This->usermode == EDITMODE)
+        return S_OK;
+
     This->usermode = EDITMODE;
 
     if(This->frame)

dlls/mshtml/tests/htmldoc.c

@@ -2571,6 +2571,10 @@ static void test_exec_editmode(IUnknown *unk)
     IOleCommandTarget_Release(cmdtrg);
 
     editmode = TRUE;
+
+    hres = IOleCommandTarget_Exec(cmdtrg, &CGID_MSHTML, IDM_EDITMODE,
+            OLECMDEXECOPT_DODEFAULT, NULL, NULL);
+    ok(hres == S_OK, "Exec failed: %08x\n", hres);
 }
 
 static HWND create_container_window(void)