Split brain: Introduce $diffbits (nfc)

Replace ${user,{,un}applied}2${,un}applied with $diffbits->{[HOA]2[HOA]}

This encapsulates the info it nicely and makes it easy to pass
it to quiltify_splitbrain, which is going to need it.

diff --git a/dgit b/dgit
index 3e4741f74a48ebbc7219cbb0505ccdf1d78523fa..08d07bec9190b600fac461f8ccb3bde037a593f2 100755 (executable)
--- a/dgit
+++ b/dgit
@@ -2539,7 +2539,8 @@ sub quiltify_tree_sentinelfiles ($) {
     return $r;
 }
 
-sub quiltify_splitbrain () {
+sub quiltify_splitbrain ($) {
+    my ($diffbits) = @_;
     # memoisation via git-reflog
     my $may_apply = $quilt_mode =~ m/gbp|unapplied/;
     die "xxx not yet implemented";
@@ -3001,14 +3002,19 @@ END
     # We calculate some guesswork now about what kind of tree this might
     # be.  This is mostly for error reporting.
 
-    my $user2unapplied    = quiltify_trees_differ($headref,   $unapplied, 1);
-    my $user2applied      = quiltify_trees_differ($headref,   $oldtiptree,1);
-    my $applied2unapplied = quiltify_trees_differ($oldtiptree,$unapplied, 1);
+    my $diffbits = {
+        # H = user's HEAD
+        # O = orig, without patches applied
+        # A = "applied", ie orig with H's debian/patches applied
+        H2O => quiltify_trees_differ($headref,  $unapplied, 1),
+        H2A => quiltify_trees_differ($headref,  $oldtiptree,1),
+        O2A => quiltify_trees_differ($unapplied,$oldtiptree,1),
+    };
 
     my @dl;
     foreach my $b (qw(01 02)) {
-        foreach my $v ($user2unapplied, $applied2unapplied, $user2applied) {
-            push @dl, ($v & $b) ? '##' : '==';
+        foreach my $v (qw(H2O O2A H2A)) {
+            push @dl, ($diffbits->{$v} & $b) ? '##' : '==';
         }
     }
     printdebug "differences \@dl @dl.\n";
@@ -3020,16 +3026,16 @@ END
                                  $dl[2],                     $dl[5];
 
     my @failsuggestion;
-    if (!($user2unapplied & $applied2unapplied)) {
+    if (!($diffbits->{H2O} & $diffbits->{O2A})) {
         push @failsuggestion, "This might be a patches-unapplied branch.";
-    }  elsif (!($user2applied & $applied2unapplied)) {
+    }  elsif (!($diffbits->{H2A} & $diffbits->{O2A})) {
         push @failsuggestion, "This might be a patches-applied branch.";
     }
     push @failsuggestion, "Maybe you need to specify one of".
         " --quilt=gbp --quilt=dpm --quilt=unapplied ?";
 
     if ($quilt_mode =~ m/gbp|dpm|apply/) {
-       quiltify_splitbrain();
+       quiltify_splitbrain($diffbits);
        return;
     }