Using `git` from `Formula#install` can cause an exec bomb if used in a
formula with `env :userpaths` because that causes both `Library/ENV/4.3`
and `Library/ENV/scm` to be in PATH, both of which contain a `git`
binary that is the same SCM wrapper. Those will mutually exec each other
indefinitely as they fail to detect that they are the same wrapper.

Extend the exec-bomb protection to check the paths after all symbolic
links have been expanded to prevent this situation.

Fixes #43.
Fixes Homebrew/homebrew-core#133.
Fixed Homebrew/homebrew-core#143.

Closes #46.

Signed-off-by: Martin Afanasjew <martin@afanasjew.de>

This can happen when `HOMEBREW_CURL` is set to brewed curl, but during

`brew resinstall curl`, brewed curl's symlink is temporary

unlinked.



So let's fallback to /usr/bin/curl in this case.

`uname -p` seems to be less useful on Linux (Debian 8 yields `unknown`),
thus prefer `uname -m` on those systems to determine the processor type.

Closes #35.

Signed-off-by: Martin Afanasjew <martin@afanasjew.de>

On Linux (and other non-OS X platforms), `HOMEBREW_OS_VERSION` was
*always* replaced with the product name, leading to less useful user
agent. E.g., on a reasonably up-to-date Debian system:
  Linuxbrew/0.9.9 (Linux; unknown Linuxbrew)

With this fix the user agent is instead (first if `lsb_release` is
available and outputs something, second otherwise):
  Linuxbrew/0.9.9 (Linux; unknown Debian GNU/Linux 8.3 (jessie))
  Linuxbrew/0.9.9 (Linux; unknown 3.16.0-4-amd64)

Bash can read directly from a file in its command substitution.

Use `printf -v` and strip out the unnecessary `echo`, thus avoiding two
unnecessary command substitutions.

For uses like this one, `case` is much more compact and easier to read.

Closes #32.

Signed-off-by: Misty De Meo <mistydemeo@github.com>

This was intended to filter out MacPorts and X11 paths, but the user
may have valid reasons to have other things here that might get linked
against.

We're not sure this is working as it was intended to, and the primary
end product so far has been making every Ruby 1.8.7 build, which is the Ruby
we use on Mavericks for compatibility, take 5-15 minutes longer per build
than 2.x Rubies.

Cumulatively this is responsible for the vast majority of CI slowness over the
last couple months as Mavericks plays catch-up and everything else waits for it
to do so.

We may revisit this in future, but for now the harm is greater than the "risk".

This technically reverts https://github.com/Homebrew/brew/commit/7b26c585c2a26ec0dad201852ca4934c77fcc493.

Closes #15.

Signed-off-by: Martin Afanasjew <martin@afanasjew.de>

Remove broken symlinks from `/Applications` and `~/Applications` that
were previously created by `brew linkapps`, but are no longer valid
because formulae were uninstalled or the provided apps have changed.

Add `--dry-run` option as is customary for destructive commands. Update
`bash` completion and man page accordingly. Also correct and update
documentation for both `brew linkapps` and `brew unlinkapps` in more
general terms.

Simplify code by using `Pathname` methods as much as possible. Also
avoid calling external commands for basic functionality like unlinking,
reduce code duplication by using a method from `cmd/linkapps.rb`, count
unlinked symlinks with `ObserverPathnameExtension`, and adjust output
for consistency with `brew linkapps`.

Simplify code by using `Pathname` methods as much as possible. Also
avoid calling external commands for basic functionality like symlink
creation, refactor code that can be shared with `brew unlinkapps`, and
print a summary line at the end (if symlinks were created).

If analytics are enabled and `brew` is used in a command substitution
context, e.g. `brew search` for tab completion, the result is that even
though the Google Analytics `curl` process runs in the background it
still is attached to the captured `stdout`, thus could theoretically
contribute to the result of the command substitution and consequently
makes the command substitution block on the completion of this process.
Redirecting `stdout` (and `stderr` for good measure) to `/dev/null`
makes this process truly asynchronous in these contexts.

Furthermore, even if the process is in the background, it is still
included in the shell's job list and thus shell internals like `wait`
(used in `cmd/update.sh`) have to wait on this process, even if they
never intended to do so. Removing the analytics process from the job
list via `disown` avoids this unintended effect.

Fixes #29.

Closes #34.

Signed-off-by: Martin Afanasjew <martin@afanasjew.de>

Fix bug introduced in a2c23dfe. Moving
this method apparently made it inaccessible from `Homebrew::Step`.

The method `fix_encoding!` is private to `Homebrew::Step` but is also
required by the `Homebrew.sanitize_output_for_xml` method for truncating
overly long logs. Move `fix_encoding!` into the `Homebrew` module to
make it accessible from both this method and the `Homebrew::Step` class.

This amends commit 343091c8.

Closes #19.

Signed-off-by: Dominyk Tiller <dominyktiller@gmail.com>

test-bot: revise Step output transcoding and XML character filtering

We need to move the Snow Leopard fix down since Etc.getgrgid can't
handle a string.

Closes #31.

Signed-off-by: ilovezfs <ilovezfs@icloud.com>

Fixes #20. Closes #23.

Makes `tap` re-runnable and unshallows when requested with `--full`.
Tapping with a different URL raises an exception.

The homebrew/core tap cannot be untapped with `untap` so running
`brew tap --full homebrew/core` is now a built-in way to get a full
clone of this tap without resorting to workarounds.

Closes #17.

Signed-off-by: ilovezfs <ilovezfs@icloud.com>

When invoking `brew tap homebrew/core`, the input options will be like
`{ :clone_target => nil }`. This renders `Hash#merge` a dead operation.

It doesn't impact Homebrew itself, but could cause problem for
downstream projects Linxubrew/Tigerbrew when they adopt core/formula
separation.

Formulae are all in taps now.

This reverts commit ceed6636.

```
==> git clean -ffdx
HEAD is now at ceed6636 test-bot: revise Step output transcoding and XML character filtering
Removing Library/Homebrew/test/.bundle/
Removing Library/Homebrew/test/fs_leak_log
Removing Library/Homebrew/test/vendor/
Error: invalid regular expression: /[^

 -uD7FFuE000-uFFFDu{10000}-u{10FFFF}]/
```
Using Ruby 1.8.

Closes #24.

Signed-off-by: Andrew Janke <andrew@apjanke.net>

Closes #50425.

Signed-off-by: Misty De Meo <mistydemeo@github.com>

Previously, superenv did not try to filter -I or -L flags
based on the list of requested dependencies; as a result, buildsystems
which opportunistically discover Homebrew-installed libraries were able
to link against them even under superenv.

This adds a list of all requested dependencies to the superenv environment,
and compares all -I and -L flags against those; any Cellar and opt paths
found which resolve to unrequested dependencies are filtered out.

Closes https://github.com/Homebrew/legacy-homebrew/pull/50462.