Under ci/ hierarchy, we run scripts under either "sh" (any Bourne
compatible POSIX shell would work) or specifically "bash" (as they
require features from bash, e.g., ${parameter/pattern/string}
expansion). As we have the CI environment under our control, we can
expect that /bin/sh will always be fine to run the scripts that only
require a Bourne shell, but we may not know where "bash" is
installed depending on the distro used.
So let's make sure we start these scripts with either one of these:
#!/bin/sh
#!/usr/bin/env bash
Yes, the latter has to assume that everybody installs "env" at that
path and not as /bin/env or /usr/local/bin/env, but this currently
is the best we could do.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As described in https://trojansource.codes/trojan-source.pdf, it is
possible to abuse directional formatting (a feature of Unicode) to
deceive human readers into interpreting code differently from compilers.
For example, an "if ()" expression could be enclosed in a comment, but
rendered as if it was outside of that comment. In effect, this could
fool a reviewer into misinterpreting the code flow as benign when it is
not.
It is highly unlikely that Git's source code wants to contain such
directional formatting in the first place, so let's just disallow it.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
