Currently, colons are considered to be part of words for the purpose of
double-click selection. This allows, for example, URLs to be selected
with a double click. This is good.
However, including colons works less well for paths that end with a colon
and whitespace--such as grep output. Removing the colon from the list
of word characters isn't a great solutionsince then URLs can no longer be
selected by double-clicking.
This patch resolves that particular issue by always omitting a colon from
double-click selection when it's immediately followed by whitespace.
BUG: 399291
FIXED-IN: 18.12.0