Double dash "--" is incorrectly changed to a hyphen &ndash

[GoogleCodeExporter]

Mark down file in gtiles with a **--text** (may require this in a header) 
results in a &ndash being output, instead of "--", which breaks searching for 
that text.

Ex:
https://code.google.com/p/chromium/codesearch#chromium/src/tools/gn/docs/referen
ce.md
"## **--args**: Specifies build arguments overrides."

Produces:
https://chromium.googlesource.com/chromium/src/+/master/tools/gn/docs/reference.
md
"–args: Specifies build arguments overrides."

But I expect:
"--args: Specifies build arguments overrides."

Original issue reported on code.google.com by scheib@chromium.org on 28 Apr 2015 at 8:35