The issue comes from the implementation of volumeSplitN() where a
driver letter (`[a-zA-Z]:`) was assumed to follow either `:`, `/`,
or `\\`.
In Windows driver letter appears in two situations:
a. `^[a-zA-Z]:` (A colon followed by `^[a-zA-Z]:` is OK as colon is
the separator in volume option)
b. A string in the format like `\\?\C:\Windows\...` (UNC).
Therefore, a driver letter can only follow either a `:` or `\\`
This PR removes the condition of `/` before the driver letter so
that options like `-v /tmp/q:/foo` could be handled correctly. A
couple of tests has also been added.
This PR fixes#20122.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
Upstream-commit: 800a7d513d3b80478a7996cb2c357b72f65e0b09
Component: engine
cd3a202f52