Commits on Aug 19, 2011
  1. want_color: automatically fallback to color.ui

    peff committed with gitster Aug 18, 2011
    All of the "do we want color" flags default to -1 to
    indicate that we don't have any color configured. This value
    is handled in one of two ways:
    
      1. In porcelain, we check early on whether the value is
         still -1 after reading the config, and set it to the
         value of color.ui (which defaults to 0).
    
      2. In plumbing, it stays untouched as -1, and want_color
         defaults it to off.
    
    This works fine, but means that every porcelain has to check
    and reassign its color flag. Now that want_color gives us a
    place to put this check in a single spot, we can do that,
    simplifying the calling code.
    
    Signed-off-by: Jeff King <peff@peff.net>
    Signed-off-by: Junio C Hamano <gitster@pobox.com>
  2. diff: don't load color config in plumbing

    peff committed with gitster Aug 18, 2011
    The diff config callback is split into two functions: one
    which loads "ui" config, and one which loads "basic" config.
    The former chains to the latter, as the diff UI config is a
    superset of the plumbing config.
    
    The color.diff variable is only loaded in the UI config.
    However, the basic config actually chains to
    git_color_default_config, which loads color.ui. This doesn't
    actually cause any bugs, because the plumbing diff code does
    not actually look at the value of color.ui.
    
    However, it is somewhat nonsensical, and it makes it
    difficult to refactor the color code. It probably came about
    because there is no git_color_config to load only color
    config, but rather just git_color_default_config, which
    loads color config and chains to git_default_config.
    
    This patch splits out the color-specific portion of
    git_color_default_config so that the diff UI config can call
    it directly. This is perhaps better explained by the
    chaining of callbacks. Before we had:
    
      git_diff_ui_config
        -> git_diff_basic_config
          -> git_color_default_config
            -> git_default_config
    
    Now we have:
    
      git_diff_ui_config
        -> git_color_config
        -> git_diff_basic_config
          -> git_default_config
    
    Signed-off-by: Jeff King <peff@peff.net>
    Signed-off-by: Junio C Hamano <gitster@pobox.com>
  3. color: delay auto-color decision until point of use

    peff committed with gitster Aug 18, 2011
    When we read a color value either from a config file or from
    the command line, we use git_config_colorbool to convert it
    from the tristate always/never/auto into a single yes/no
    boolean value.
    
    This has some timing implications with respect to starting
    a pager.
    
    If we start (or decide not to start) the pager before
    checking the colorbool, everything is fine. Either isatty(1)
    will give us the right information, or we will properly
    check for pager_in_use().
    
    However, if we decide to start a pager after we have checked
    the colorbool, things are not so simple. If stdout is a tty,
    then we will have already decided to use color. However, the
    user may also have configured color.pager not to use color
    with the pager. In this case, we need to actually turn off
    color. Unfortunately, the pager code has no idea which color
    variables were turned on (and there are many of them
    throughout the code, and they may even have been manipulated
    after the colorbool selection by something like "--color" on
    the command line).
    
    This bug can be seen any time a pager is started after
    config and command line options are checked. This has
    affected "git diff" since 89d07f7 (diff: don't run pager if
    user asked for a diff style exit code, 2007-08-12). It has
    also affect the log family since 1fda91b (Fix 'git log'
    early pager startup error case, 2010-08-24).
    
    This patch splits the notion of parsing a colorbool and
    actually checking the configuration. The "use_color"
    variables now have an additional possible value,
    GIT_COLOR_AUTO. Users of the variable should use the new
    "want_color()" wrapper, which will lazily determine and
    cache the auto-color decision.
    
    Signed-off-by: Jeff King <peff@peff.net>
    Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commits on Aug 18, 2011
  1. git_config_colorbool: refactor stdout_is_tty handling

    peff committed with gitster Aug 18, 2011
    Usually this function figures out for itself whether stdout
    is a tty. However, it has an extra parameter just to allow
    git-config to override the auto-detection for its
    --get-colorbool option.
    
    Instead of an extra parameter, let's just use a global
    variable. This makes calling easier in the common case, and
    will make refactoring the colorbool code much simpler.
    
    Signed-off-by: Jeff King <peff@peff.net>
    Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commits on Dec 10, 2010
  1. default color.status.branch to "same as header"

    peff committed with gitster Dec 9, 2010
    This gives it the same behavior as we had prior to 1d28232
    (status: show branchname with a configurable color).
    
    To do this we need the concept of a "NIL" color, which is
    provided by color.[ch]. The implementation is very simple;
    in particular, there are no precautions taken against code
    accidentally printing the NIL. This should be fine in
    practice because:
    
      1. You can't input a NIL color in the config, so it must
         come from the in-code defaults. Which means it is up
         the client code to handle the NILs it defines.
    
      2. If we do ever print a NIL, it will be obvious what the
         problem is, and the bug can be fixed.
    
    Signed-off-by: Jeff King <peff@peff.net>
    Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commits on Jan 18, 2009
  1. color: make it easier for non-config to parse color specs

    peff committed with gitster Jan 17, 2009
    We have very featureful color-parsing routines which are
    used for color.diff.* and other options. Let's make it
    easier to use those routines from other parts of the code.
    
    This patch adds a color_parse_mem() helper function which
    takes a length-bounded string instead of a NUL-terminated
    one. While the helper is only a few lines long, it is nice
    to abstract this out so that:
    
     - callers don't forget to free() the temporary buffer
    
     - right now, it is implemented in terms of color_parse().
       But it would be more efficient to reverse this and
       implement color_parse in terms of color_parse_mem.
    
    This also changes the error string for an invalid color not
    to mention the word "config", since it is not always
    appropriate (and when it is, the context is obvious since
    the offending config variable is given).
    
    Finally, while we are in the area, we clean up the parameter
    names in the declaration of color_parse; the var and value
    parameters were reversed from the actual implementation.
    
    Signed-off-by: Jeff King <peff@peff.net>
    Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commits on Dec 11, 2007
  1. Support GIT_PAGER_IN_USE environment variable

    peff committed with gitster Dec 11, 2007
    When deciding whether or not to turn on automatic color
    support, git_config_colorbool checks whether stdout is a
    tty. However, because we run a pager, if stdout is not a
    tty, we must check whether it is because we started the
    pager. This used to be done by checking the pager_in_use
    variable.
    
    This variable was set only when the git program being run
    started the pager; there was no way for an external program
    running git indicate that it had already started a pager.
    This patch allows a program to set GIT_PAGER_IN_USE to a
    true value to indicate that even though stdout is not a tty,
    it is because a pager is being used.
    
    Signed-off-by: Jeff King <peff@peff.net>
    Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commits on Sep 8, 2006
  1. Move color option parsing out of diff.c and into color.[ch]

    peff committed with Junio C Hamano Sep 8, 2006
    The intent is to lib-ify colorizing code so it can be reused.
    
    Signed-off-by: Jeff King <peff@peff.net>
    Signed-off-by: Junio C Hamano <junkio@cox.net>