+++ This bug was initially created as a clone of Bug #856270 +++ > 1049 [NNNNN] WARNING: NS_ENSURE_SUCCESS(rv, rv) failed with result 0x80004005: file extensions/spellcheck/src/mozInlineSpellChecker.cpp, line 1995 It looks like we're properly handling the failure case, perhaps we should remove the warning. This warning [1], introduced in bug 856270, shows up in the following test suites: > mozilla-central_ubuntu64_vm-debug_test-mochitest-other-bm53-tests1-linux64-build0.txt:667 > mozilla-central_ubuntu64_vm-debug_test-mochitest-2-bm67-tests1-linux64-build1.txt:117 > mozilla-central_ubuntu64_vm-debug_test-mochitest-e10s-2-bm53-tests1-linux64-build12.txt:98 > mozilla-central_ubuntu64_vm-debug_test-mochitest-4-bm121-tests1-linux64-build0.txt:59 > mozilla-central_ubuntu64_vm-debug_test-mochitest-e10s-4-bm122-tests1-linux64-build12.txt:54 > mozilla-central_ubuntu64_vm-debug_test-mochitest-e10s-1-bm123-tests1-linux64-build25.txt:19 > mozilla-central_ubuntu64_vm-debug_test-mochitest-e10s-5-bm52-tests1-linux64-build2.txt:11 > mozilla-central_ubuntu64_vm-debug_test-mochitest-5-bm115-tests1-linux64-build29.txt:11 > mozilla-central_ubuntu64_vm-debug_test-mochitest-1-bm117-tests1-linux64-build1.txt:8 > mozilla-central_ubuntu64_vm-debug_test-crashtest-bm53-tests1-linux64-build28.txt:3 > mozilla-central_ubuntu64_vm-debug_test-reftest-e10s-1-bm68-tests1-linux64-build0.txt:1 > mozilla-central_ubuntu64_vm-debug_test-reftest-2-bm53-tests1-linux64-build27.txt:1 It shows up in 33 tests. A few of the most prevalent: > 650 - widget/tests/test_imestate.html > 196 - dom/html/test/test_bug430351.html > 54 - dom/tests/mochitest/general/test_bug1012662_editor.html > 30 - dom/events/test/test_bug409604.html > 18 - editor/libeditor/tests/test_contenteditable_focus.html > 16 - editor/libeditor/tests/test_bug551704.html > 10 - layout/base/tests/test_event_target_radius.html > 8 - layout/base/tests/test_touchcaret_visibility.html > 8 - editor/libeditor/tests/test_bug578771.html > 8 - dom/base/test/test_copypaste.html [1] https://hg.mozilla.org/mozilla-central/annotate/49683d4e9ebd/extensions/spellcheck/src/mozInlineSpellChecker.cpp#l1995

This is the #5 most verbose warning during testing.

I thought this would be a quick fix, but we should probably find out why the call is failing. Maybe it's nothing, but maybe not. I'll be away next week so I won't be able to work on it soon.

UpdateCurrentDictionary can fail because of a host of reasons, including entirely possible stuff such as there being no document element! We shouldn't really warn every time about this, since a lot of those error cases come from stuff under the control of content.