User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; ru; rv:1.9.0.3) Gecko/2008092417 Firefox/3.0.3 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; ru; rv:1.9.1b1) Gecko/20081007 Firefox/3.1b1 After undo operation Next/Prev buttons may be enabled when the input field is empty and vice versa. Reproducible: Always Steps to Reproduce: 1. Start Firefox, open blank page 2. Press Ctrl+F to open find bar 3. Type "abcd", then delete it using backspace and type "qwerty" 4. Press Ctrl+Z. Textbox is clear now 5. Press Ctrl+Z again. It's "abcd" here again. Actual Results: After step 4 (when textbox is empty) toolbar buttons are still enabled. After step 5 (when textbox contains "abcd") toolbar buttons are disabled. Expected Results: After step 4 (when textbox is empty) toolbar buttons should become disabled. After step 5 (when textbox contains "abcd") toolbar buttons should be enabled again. After step 4 if you press Next button they become disabled. If you press Ctrl+Z now textbox will contain "abcd" but toolbar will still be disabled. Reproducible in Firefox 2.0, 3.0 and 3.1b1 Workaround: after field is somehow changed (for example, last letter is deleted) findbar becomes enabled.

Confirmed on linux on trunk.

This should be fixed by the landing of bug 318065 on mozilla-central (http://hg.mozilla.org/mozilla-central/rev/170e2522e530)