add cross-level commit script

Author: fantasai

bin/xcommit.pl

@@ -0,0 +1,85 @@
+#!/usr/bin/perl
+
+use strict;
+
+my $sourcedir = shift @ARGV;
+
+unless ($sourcedir) {
+  print <<XXX;
+= CSSWG Cross-Level Commit Script =
+
+This script takes diffs from the specified directory,
+applies them to all of that module’s specs with a higher level number,
+and issues a `git commit` command if requested.
+
+cross-commit.pl SPECDIR
+
+For example,
+  xcommit.pl css-grid-1
+or
+  xcommit.pl . # e.g. css-grid-1 as current dir
+
+Your system’s `git` and `patch` commands are used.
+Failed patches will be handled as usual for `patch`,
+and will cause the commit to abort so you can fix it up
+and commit manually.
+
+Note: Assumes shortname-N naming scheme for SPECDIR and friends
+at only one level of depth below git repo root.
+XXX
+  exit;
+}
+
+# Too lazy to look up the right way to do this
+chdir $sourcedir || die "Invalid source directory: $!";
+$sourcedir = `pwd`;
+chomp $sourcedir;
+
+# extract info
+$sourcedir =~ m#(.*)/([^/]+)-([\d+])$#;
+my $rootdir = $1;
+my $specname = $2;
+my $speclevel = $3;
+my @failed = ();
+
+# confirm before continuing
+print "Sourcing diffs from $specname level $speclevel under root $rootdir:\n";
+chdir $rootdir;
+$_ = `ls -d $specname-*`;
+my @dirlist = split;
+print "Matching specs: @dirlist\n";
+
+print "Press enter to continue, q to quit:";
+$_ = <STDIN>;
+chomp;
+exit if ($_);
+
+# main patching loop
+foreach (@dirlist) {
+  /(\d+)$/;
+  my $level = $1;
+  if ($level > $speclevel) {
+    print "\nPatching $_ ...\n";
+    chdir $_;
+    print `git diff $sourcedir | patch -p2`;
+    push @failed, $specname . '-' . $speclevel if $?;
+    chdir $rootdir;
+  }
+}
+
+# wrap it up
+if (@failed == 0) {
+  my $dirs = join ' ', @dirlist;
+  print "\n\nWould you like me to issue `git commit $dirs`?\n";
+  print "Enter arguments (e.g. -m 'message' --amend) or leave blank to skip commit.\n";
+  print "git commit : ";
+  my $args = <STDIN>;
+  chomp $args;
+  if ($args) {
+    print "Executing git commit $args $dirs ...\n\n";
+    exec "git commit $args $dirs";
+  }
+}
+else {
+  die "Patching failed for @failed, please fix and commit manually.\n";
+}