From bd958e91dffdba00ef94dc9bfc04b46599362f9a Mon Sep 17 00:00:00 2001 From: Scott Baker Date: Mon, 23 Mar 2026 02:02:15 -0400 Subject: [PATCH] diff-highlight: allow module callers to pass in color config Users of the module may want to pass in their own color config for a few obvious reasons: - they are pulling the config from different variables than diff-highlight itself uses - they are loading the config in a more efficient way (say, by parsing git-config --list) and don't want to incur the six (!) git-config calls that DiffHighlight.pm runs to check all config Let's allow users of the module to pass in the color config, and lazy-load it when needed if they haven't. Signed-off-by: Scott Baker Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- contrib/diff-highlight/DiffHighlight.pm | 41 +++++++++++++++++-------- contrib/diff-highlight/README | 6 ++++ 2 files changed, 35 insertions(+), 12 deletions(-) diff --git a/contrib/diff-highlight/DiffHighlight.pm b/contrib/diff-highlight/DiffHighlight.pm index a5e5de3b18..96369eadf9 100644 --- a/contrib/diff-highlight/DiffHighlight.pm +++ b/contrib/diff-highlight/DiffHighlight.pm @@ -9,18 +9,11 @@ use File::Spec; my $NULL = File::Spec->devnull(); -# Highlight by reversing foreground and background. You could do -# other things like bold or underline if you prefer. -my @OLD_HIGHLIGHT = ( - color_config('color.diff-highlight.oldnormal'), - color_config('color.diff-highlight.oldhighlight', "\x1b[7m"), - color_config('color.diff-highlight.oldreset', "\x1b[27m") -); -my @NEW_HIGHLIGHT = ( - color_config('color.diff-highlight.newnormal', $OLD_HIGHLIGHT[0]), - color_config('color.diff-highlight.newhighlight', $OLD_HIGHLIGHT[1]), - color_config('color.diff-highlight.newreset', $OLD_HIGHLIGHT[2]) -); +# The color theme is initially set to nothing here to allow outside callers +# to set the colors for their application. If nothing is sent in we use +# colors from git config in load_color_config(). +our @OLD_HIGHLIGHT = (); +our @NEW_HIGHLIGHT = (); my $RESET = "\x1b[m"; my $COLOR = qr/\x1b\[[0-9;]*m/; @@ -170,6 +163,29 @@ sub show_hunk { $line_cb->(@queue); } +sub load_color_config { + # If the colors were NOT set from outside this module we load them on-demand + # from the git config. Note that only one of elements 0 and 2 in each + # array is used (depending on whether you are doing set/unset on an + # attribute, or specifying normal vs highlighted coloring). So we use + # element 1 as our check for whether colors were passed in; it should + # always be set if you want highlighting to do anything. + if (!defined $OLD_HIGHLIGHT[1]) { + @OLD_HIGHLIGHT = ( + color_config('color.diff-highlight.oldnormal'), + color_config('color.diff-highlight.oldhighlight', "\x1b[7m"), + color_config('color.diff-highlight.oldreset', "\x1b[27m") + ); + } + if (!defined $NEW_HIGHLIGHT[1]) { + @NEW_HIGHLIGHT = ( + color_config('color.diff-highlight.newnormal', $OLD_HIGHLIGHT[0]), + color_config('color.diff-highlight.newhighlight', $OLD_HIGHLIGHT[1]), + color_config('color.diff-highlight.newreset', $OLD_HIGHLIGHT[2]) + ); + }; +} + sub highlight_pair { my @a = split_line(shift); my @b = split_line(shift); @@ -218,6 +234,7 @@ sub highlight_pair { } if (is_pair_interesting(\@a, $pa, $sa, \@b, $pb, $sb)) { + load_color_config(); return highlight_line(\@a, $pa, $sa, \@OLD_HIGHLIGHT), highlight_line(\@b, $pb, $sb, \@NEW_HIGHLIGHT); } diff --git a/contrib/diff-highlight/README b/contrib/diff-highlight/README index 9c89146fb0..ed8d876a18 100644 --- a/contrib/diff-highlight/README +++ b/contrib/diff-highlight/README @@ -138,6 +138,12 @@ Your script may set up one or more of the following variables: processing a logical chunk of input). The default function flushes stdout. + - @DiffHighlight::OLD_HIGHLIGHT and @DiffHighlight::NEW_HIGHLIGHT - these + arrays specify the normal, highlighted, and reset colors (in that order) + for old/new lines. If unset, values will be retrieved by calling `git + config` (see "Color Config" above). Note that these should be the literal + color bytes (starting with an ANSI escape code), not color names. + The script may then feed lines, one at a time, to DiffHighlight::handle_line(). When lines are done processing, they will be fed to $line_cb. Note that DiffHighlight may queue up many input lines (to analyze a whole hunk)