Tests can now be specified as a block in the DSL. A temporary test
directory is set up automatically when calling Formula#test. The
semantics of the test remain the same: the block can either raise an
exception or return false to signal failure.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

Closes Homebrew/homebrew#16280.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Closes Homebrew/homebrew#16901.

Superenv scripts have a stripped PATH, which may not include
the brew binary itself. Make this explicitly available to
superenv scripts.

Fixes bsdmake wrapper.

Closes Homebrew/homebrew#16805.
Closes Homebrew/homebrew#16846.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Fixes Homebrew/homebrew#16857.

Probably a better approach than reverted e721c7.

Fixes Homebrew/homebrew#16604.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

Xcode.prefix and Xcode.installed? use slightly different heuristics to
find Xcode. In fact, .installed? basically duplicates a portion of the
.prefix logic. In practice, the methods results are usually consistent,
but .installed? does not handle non-standard prefixes if mdfind cannot
locate Xcode (for example, if the user has disabled Spotlight indexing).

Since .installed? is essentially a subset of the .prefix logic, we can
rely on the result from .prefix instead.

Fixes Homebrew/homebrew#16790.

@sceaga has discontinued his homebrew fork, so tigerbrew is now PPC/
Tiger users' best bet.

Originally written for tigerbrew, but useful enough for core.
Replaces the shelled-out which in utils.rb with a native-ruby
equivalent, which is moderately faster.

Closes Homebrew/homebrew#16659.

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

* Remove the unused HTML and commenting features.
* Return a good status code.
* Print command output on failure.
* Test bottle installation.

c.f. Homebrew/homebrew#16296.

c.f. Homebrew/homebrew#16688.

Pass the `--no-pager` flag to git when grabbing a diff summary for a patch as
there is no good reason to invoke a pager for ~2-10 lines that the user must
then exit manually.

Fixes Homebrew/homebrew#16655.

Two issues were preventing `brew upgrade` from functioning properly:

  - `Tab.for_formula` was used to recover options from prior installs. The
    problem is that during an upgrade `for_formula` will be directed to a
    non-existant install of the newer version and thus returns a forged tab
    claiming no options were invoked.

  - The assignment to `installer.install_bottle` requires parenthesis in order
    to function properly.

closes Homebrew/homebrew#15853.

This code makes assumptions about the existence of prefix which are
valid in the context of the installer, but not necessarily in the
context of `brew info`, thus `brew info` on an outdated formula errors
out.

This reverts commit e5b53dd64b769b67805d1054d906f7083939d905.

Closes Homebrew/homebrew#16604.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>