Some setenv() implementations (e.g. the one in OpenBSD's stdlib)
segfault if we pass a NULL value. Only set environment variables if the
corresponding settings are defined to avoid this.

Note that this is a minor behaviour change as environment variables were
supposed to be set to an empty string if a setting was undefined. Given
that this feature isn't part of any official release yet, there's no
need to worry about backwards compatibility, really. Change the
documentation accordingly.

Signed-off-by: Lukas Fleischer <cgit@cryptocrack.de>

For sites that do not want to configure mime types by hand but
still want the correct mime type for 'plain' blobs, configuring
a mime type file is made possible. This is handy since such a
file is normally already provided (at least on Linux systems).

Also, this reflects the gitweb option '$mimetypes_file'

Signed-off-by: Ferry Huberts <ferry.huberts@pelagic.nl>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>

This is a saner alternative than hardcoding the default branch to be
"master". The add_repo() function will now check for a symbolic ref in
repo_path/HEAD. If there is a suitable one, overwrite repo->defbranch
with it. Note that you'll need to strip the newline from the file (->
len-17).

If HEAD is a symbolic link pointing directly to a branch below
refs/heads/, do a readlink() instead to find the ref name.

Signed-off-by: Julius Plenz <plenz@cis.fu-berlin.de>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>

The old default value was an abomination which never should have been
allowed to see the light of day.

This patch removes the default, which is a backwards incompatible change
with low probability of causing anyone any real trouble (a repo with
submodules, displayed by cgit using the default value of `module-link`,
is very unlikely to actually generate working links).

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

The current 'repo.module-link' option is sufficient when all gitlinks
in a repository can be converted to commit links in a uniform way, but
not when different submodules/paths needs different settings.

This patch adds support for 'repo.module-link.<path>', which will be
used for linking to submodules at paths matching one such entry.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

The global module-link option can be overridden per repo, but this has
never been documented.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>