[PATCH 1/3] chainlint: sidestep impoverished macOS "terminfo"

["Eric Sunshine via GitGitGadget" <gitgitgadget@gmail.com>]

From: Eric Sunshine <sunshine@sunshineco.com>

Although the macOS Terminal.app is "xterm"-compatible, its corresponding
"terminfo" entry neglects to mention capabilities which Terminal.app
actually supports (such as "dim text"). This oversight on Apple's part
ends up penalizing users of "good citizen" console programs which
consult "terminfo" to tailor their output based upon reported terminal
capabilities (as opposed to programs which assume that the terminal
supports ANSI codes).

Sidestep this Apple problem by imbuing get_colors() with specific
knowledge of "xterm" capabilities rather than trusting "terminfo" to
report them correctly. Although hard-coding such knowledge is ugly,
"xterm" support is nearly ubiquitous these days, and Git itself sets
precedence by assuming support for ANSI color codes. For non-"xterm",
fall back to querying "terminfo" via `tput` as usual.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
---
 t/chainlint.pl | 35 +++++++++++++++++++++++------------
 1 file changed, 23 insertions(+), 12 deletions(-)

diff --git a/t/chainlint.pl b/t/chainlint.pl
index 7972c5bbe6f..fcf4d459249 100755
--- a/t/chainlint.pl
+++ b/t/chainlint.pl
@@ -653,21 +653,32 @@ my @NOCOLORS = (bold => '', rev => '', reset => '', blue => '', green => '', red
 my %COLORS = ();
 sub get_colors {
 	return \%COLORS if %COLORS;
-	if (exists($ENV{NO_COLOR}) ||
-	    system("tput sgr0 >/dev/null 2>&1") != 0 ||
-	    system("tput bold >/dev/null 2>&1") != 0 ||
-	    system("tput rev  >/dev/null 2>&1") != 0 ||
-	    system("tput setaf 1 >/dev/null 2>&1") != 0) {
+	if (exists($ENV{NO_COLOR})) {
 		%COLORS = @NOCOLORS;
 		return \%COLORS;
 	}
-	%COLORS = (bold  => `tput bold`,
-		   rev   => `tput rev`,
-		   reset => `tput sgr0`,
-		   blue  => `tput setaf 4`,
-		   green => `tput setaf 2`,
-		   red   => `tput setaf 1`);
-	chomp(%COLORS);
+	if ($ENV{TERM} =~ /\bxterm\b/) {
+		%COLORS = (bold  => "\e[1m",
+			   rev   => "\e[7m",
+			   reset => "\e[0m",
+			   blue  => "\e[34m",
+			   green => "\e[32m",
+			   red   => "\e[31m");
+		return \%COLORS;
+	}
+	if (system("tput sgr0 >/dev/null 2>&1") == 0 &&
+	    system("tput bold >/dev/null 2>&1") == 0 &&
+	    system("tput rev  >/dev/null 2>&1") == 0 &&
+	    system("tput setaf 1 >/dev/null 2>&1") == 0) {
+		%COLORS = (bold  => `tput bold`,
+			   rev   => `tput rev`,
+			   reset => `tput sgr0`,
+			   blue  => `tput setaf 4`,
+			   green => `tput setaf 2`,
+			   red   => `tput setaf 1`);
+		return \%COLORS;
+	}
+	%COLORS = @NOCOLORS;
 	return \%COLORS;
 }
 
-- 
gitgitgadget