use normalise-mrconfig instead of a symlink

This means we can get rid of chain loading of ~/src/.mrconfig, which
has various issues.

3 files changed, 98 insertions, 5 deletions

diff --git a/bin/bstraph.sh b/bin/bstraph.sh
index 8d79fbfc..6d341594 100755
--- a/bin/bstraph.sh
+++ b/bin/bstraph.sh
@@ -10,7 +10,8 @@ set -e
 
 # ---- Perform the bootstrap
 
-mr -t --config $HOME/src/dotfiles/home-mrconfig -d $HOME/src/dotfiles fixups
+$HOME/src/dotfiles/bin/normalise-mrconfig
+mr -d $HOME/src/dotfiles fixups
 mr -d $HOME/src/dotfiles stow
 
 echo "I: dotfiles bootstrap successful"
diff --git a/bin/normalise-mrconfig b/bin/normalise-mrconfig
new file mode 100755
index 00000000..20ad333b
--- /dev/null
+++ b/bin/normalise-mrconfig
@@ -0,0 +1,95 @@
+#!/usr/bin/env perl
+
+# normalise-mrconfig -- regenerate ~/.mrconfig
+
+# Copyright (C) 2019 Sean Whitton
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or (at
+# your option) any later version.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+
+# This script must be as portable as possible (inc. its shebang).
+
+use strict;
+use warnings;
+use autodie;
+
+sub blocks_from_file ($);
+sub say_block        (*$$);
+
+exit main();
+
+sub main {
+    my $master = $ENV{HOME} . "/src/dotfiles/.mrconfig.in";
+    my $target = $ENV{HOME} . "/.mrconfig";
+
+    unlink $target unless -f $target;
+
+    my %master_blocks = blocks_from_file($master);
+    my %target_blocks = -f $target ? blocks_from_file($target) : undef;
+    for (keys %master_blocks) {
+        $master_blocks{$_} = "# DO NOT EDIT THIS BLOCK; automatically updated\n"
+          . join "\n", grep !/^\s*#/, grep !/^\s*$/,
+          split "\n", $master_blocks{$_};
+    }
+    for (keys %target_blocks) {
+        delete $target_blocks{$_} if exists $master_blocks{$_};
+    }
+
+    open my $fh, '>', $target;
+    print $fh "# -*- mode: conf -*-\n";
+
+    # any DEFAULT has to come first to have effect on the proceding
+    # blocks
+    if (defined $master_blocks{"DEFAULT"}) {
+        say_block($fh, "DEFAULT", $master_blocks{"DEFAULT"});
+        delete $master_blocks{"DEFAULT"};
+    } elsif (defined $target_blocks{"DEFAULT"}) {
+        say_block($fh, "DEFAULT", $target_blocks{"DEFAULT"});
+        delete $target_blocks{"DEFAULT"};
+    }
+    # put the master blocks in first, so that by default mr processes
+    # those repos first
+    say_block($fh, $_, $master_blocks{$_}) foreach keys %master_blocks;
+    # finally, remaining target blocks
+    say_block($fh, $_, $target_blocks{$_}) foreach keys %target_blocks;
+
+    return 0;
+}
+
+sub blocks_from_file ($) {
+    my $file = shift;
+
+    my %blocks;
+    my $current_block;
+    open my $fh, '<', $file;
+    while (<$fh>) {
+        if (/^\[(.+)\]$/) {
+            $current_block = $1;
+        } elsif (defined $current_block) {
+            $blocks{$current_block} .= $_;
+        }
+    }
+    # drop trailing newlines from the text of each block
+    { local $/ = ''; chomp $blocks{$_} foreach keys %blocks }
+    return %blocks;
+}
+
+sub say_block (*$$) {
+    my ($fh, $block, $text) = @_;
+
+    print $fh "\n[$block]\n";
+    print $fh $text;
+    print $fh "\n";
+}
diff --git a/bin/src-register-all b/bin/src-register-all
index 0c993097..5d5bae59 100755
--- a/bin/src-register-all
+++ b/bin/src-register-all
@@ -13,10 +13,7 @@ use File::chdir;
 foreach my $f ( glob "$ENV{'HOME'}/src/*" ) {
     my $short = basename($f);
     next unless ( -d "$f/.git" || -d "$f/.hg" );
-    unless ( (fgrep { /^\[$short\]$/ }
-              "$ENV{'HOME'}/src/.mrconfig")
-             || (fgrep { /^\[\$HOME\/src\/$short\]$/ }
-                 "$ENV{'HOME'}/.mrconfig") ) {
+    {
         local $CWD = $f;
         system "mr register >/dev/null";
         die "failed to register ~/src/$short" unless ($? >> 8 == 0);