X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=dgit;h=31e6bd581b7453d23519d9aa01983e5b21061e4a;hb=89b8afb34a970cb6f31f5725f38c2f51203c6a29;hp=33e32395a3efb548618a0ea45da6d6e5cf68fcdb;hpb=ef028a9a6672e0d7ecf3a031f7e15d6f20612ec5;p=dgit.git

diff --git a/dgit b/dgit
index 33e32395..31e6bd58 100755
--- a/dgit
+++ b/dgit
@@ -30,6 +30,8 @@ use File::Path;
 use File::Temp qw(tempdir);
 use File::Basename;
 use Dpkg::Version;
+use Dpkg::Compression;
+use Dpkg::Compression::Process;
 use POSIX;
 use IPC::Open2;
 use Digest::SHA;
@@ -4188,7 +4190,7 @@ END
 		quilt_check_splitbrain_cache($actualhead, $upstreamversion);
 	    $dgithead or fail
  "--quilt=$quilt_mode but no cached dgit view:
- perhaps tree changed since dgit build[-source] ?";
+ perhaps HEAD changed since dgit build[-source] ?";
 	    $split_brain = 1;
 	    $dgithead = splitbrain_pseudomerge($clogp,
 					       $actualhead, $dgithead,
@@ -4238,13 +4240,42 @@ END
     my $r = system @diffcmd;
     if ($r) {
 	if ($r==256) {
+	    my $referent = $split_brain ? $dgithead : 'HEAD';
 	    my $diffs = cmdoutput @git, qw(diff --stat), $tree, $dgithead;
-	    fail <<END
+
+	    my @mode_changes;
+	    my $raw = cmdoutput @git,
+		qw(diff --no-renames -z -r --raw), $tree, $dgithead;
+	    my $changed;
+	    foreach (split /\0/, $raw) {
+		if (defined $changed) {
+		    push @mode_changes, "$changed: $_\n" if $changed;
+		    $changed = undef;
+		    next;
+		} elsif (m/^:0+ 0+ /) {
+		    $changed = '';
+		} elsif (m/^:(?:10*)?(\d+) (?:10*)?(\d+) /) {
+		    $changed = "Mode change from $1 to $2"
+		} else {
+		    die "$_ ?";
+		}
+	    }
+	    if (@mode_changes) {
+		fail <<END.(join '', @mode_changes).<<END;
+HEAD specifies a different tree to $dscfn:
+$diffs
+END
+There is a problem with your source tree (see dgit(7) for some hints).
+To see a full diff, run git diff $tree $referent
+END
+	    }
+
+	    fail <<END;
 HEAD specifies a different tree to $dscfn:
 $diffs
 Perhaps you forgot to build.  Or perhaps there is a problem with your
  source tree (see dgit(7) for some hints).  To see a full diff, run
-   git diff $tree HEAD
+   git diff $tree $referent
 END
 	} else {
 	    failedcmd @diffcmd;