<p dir="auto">Safari 6.0.5 / Bootstrap 3 RC2</p>
<p dir="auto">Snippet <a href="http://jsfiddle.net/DQheE/3/" rel="nofollow">http://jsfiddle.net/DQheE/3/</a></p>
<ol dir="auto">
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<p dir="auto">Click Dropdown (horizontal navbar)<br>
<a target="_blank" rel="noopener noreferrer nofollow" href="https://camo.githubusercontent.com/ac2c0e80964d3035487ee1266406cf9a801766b48f94d9908846dfb75d967b8d/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f333838333831352f3936353934382f37313864356231302d303533382d313165332d383836322d3766633961306130633733632e706e67"><img src="https://camo.githubusercontent.com/ac2c0e80964d3035487ee1266406cf9a801766b48f94d9908846dfb75d967b8d/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f333838333831352f3936353934382f37313864356231302d303533382d313165332d383836322d3766633961306130633733632e706e67" alt="jsfiddle net_dqhee_3_embedded_result_" data-canonical-src="https://f.cloud.github.com/assets/3883815/965948/718d5b10-0538-11e3-8862-7fc9a0a0c73c.png" style="max-width: 100%;"></a></p>
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<p dir="auto">Click Dropdown again (collapsed navbar)<br>
<a target="_blank" rel="noopener noreferrer nofollow" href="https://camo.githubusercontent.com/d03550b4c505c3acf31e4fdefc6da307f93798972f34ed72e31b8961aa9e8d70/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f333838333831352f3936353935332f38626165373166612d303533382d313165332d396639312d3530666630376132386532332e706e67"><img src="https://camo.githubusercontent.com/d03550b4c505c3acf31e4fdefc6da307f93798972f34ed72e31b8961aa9e8d70/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f333838333831352f3936353935332f38626165373166612d303533382d313165332d396639312d3530666630376132386532332e706e67" alt="jsfiddle net_dqhee_3_embedded_result__1" data-canonical-src="https://f.cloud.github.com/assets/3883815/965953/8bae71fa-0538-11e3-9f91-50ff07a28e23.png" style="max-width: 100%;"></a></p>
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<p dir="auto">Resize navbar and click Dropdown again (it get cropped)<br>
<a target="_blank" rel="noopener noreferrer nofollow" href="https://camo.githubusercontent.com/efd8787e3611ede7d728159eda66adb91e0159eb0a62bf935cf22af2a8e37a62/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f333838333831352f3936353935362f61633263306637382d303533382d313165332d393961352d3631323733303763383836362e706e67"><img src="https://camo.githubusercontent.com/efd8787e3611ede7d728159eda66adb91e0159eb0a62bf935cf22af2a8e37a62/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f333838333831352f3936353935362f61633263306637382d303533382d313165332d393961352d3631323733303763383836362e706e67" alt="edit_this_fiddle_-_jsfiddle-2" data-canonical-src="https://f.cloud.github.com/assets/3883815/965956/ac2c0f78-0538-11e3-99a5-6127307c8866.png" style="max-width: 100%;"></a></p>
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<p dir="auto">Scrollbars show for the y-overflow when moving from collapse to full width and a dropdown is open in the navbar.</p>
<p dir="auto">To reproduce, shrink the browser window down to where the nav collapses and then open a dropdown causing the nav to overflow and show the scroll bar. Then, resize back to full width without first closing the nav. Because the <code class="notranslate">collapse</code> class is no longer on the <code class="notranslate">navbar-collapse</code> div, the navbar shows the scrollbars because its overflow-y is set to auto;</p>
<p dir="auto">I was seeing this while using latest version of Chrome on Windows. Haven't looked in other browsers.</p>
<p dir="auto">The following LESS Fixes the issue:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="@media screen and (min-width: @grid-float-breakpoint) {
    .navbar-collapse {
        overflow: visible !important;
    }
}"><pre class="notranslate"><code class="notranslate">@media screen and (min-width: @grid-float-breakpoint) {
    .navbar-collapse {
        overflow: visible !important;
    }
}
</code></pre></div>