wptexturize inconsistent with em dashes (sometimes returns -- as a single en dash)

[andrealeebishop]

​http://codex.wordpress.org/Function_Reference/wptexturize

When I add ​this content to the Text tab or Visual tab of the post, not all of the double dashes are returned as an em dash.

Examples:
​http://andrealeebishop.wpsandbox.me/?p=49 (content ​https://cloudup.com/cUfB8EYZVWe )
​http://andrealeebishop.wpsandbox.me/?p=58 (content ​https://cloudup.com/cZFVkdUY7mM )

It is repeatable, but difficult to narrow down for steps to reproduce. nbsp's show up around the single dash when Inspect Element is used.

[miqrogroove]

I can see a pattern to the output for any \xC2\xA0-- but I can't get my server to do the same.

I see you have PHP 5.5.14. Could you tell us which server operating system and any other pertinent details?

[miqrogroove]

Also note this is quite old and is not the trunk version. I can probably point you to the problem now.

<meta·name="generator"·content="WordPress·4.0-alpha-20140608"·/>(LF)

[miqrogroove]

Duplicate of #23185.

OP results not based on trunk version. Bug was a duplicate of a fixed issue and was not a regression from 3.9.