git-archimport: support empty summaries, put summary on a single line.

Don't fail if the summary line in an arch commit is empty.  In this case,
try to use the first line in the commit message followed by an ellipsis.
In addition, if the summary is multi-line, it is joined on a single line.

Signed-off-by: Junio C Hamano <junkio@cox.net>

git-archimport.perl

@@ -553,7 +553,7 @@ foreach my $ps (@psets) {
 
     my $pid = open2(*READER, *WRITER,'git-commit-tree',$tree,@par) 
         or die $!;
-    print WRITER $ps->{summary},"\n";
+    print WRITER $ps->{summary},"\n\n";
     print WRITER $ps->{message},"\n";
     
     # make it easy to backtrack and figure out which Arch revision this was:
@@ -755,7 +755,8 @@ sub parselog {
             $ps->{tag} = $1;
             $key = undef;
         } elsif (/^Summary:\s*(.*)$/ ) {
-            # summary can be multiline as long as it has a leading space
+            # summary can be multiline as long as it has a leading space.
+	    # we squeeze it onto a single line, though.
             $ps->{summary} = [ $1 ];
             $key = 'summary';
         } elsif (/^Creator: (.*)\s*<([^\>]+)>/) {
@@ -787,8 +788,18 @@ sub parselog {
         }
     }
    
-    # post-processing:
-    $ps->{summary} = join("\n",@{$ps->{summary}})."\n";
+    # drop leading empty lines from the log message
+    while (@$log && $log->[0] eq '') {
+	shift @$log;
+    }
+    if (exists $ps->{summary} && @{$ps->{summary}}) {
+	$ps->{summary} = join(' ', @{$ps->{summary}});
+    }
+    elsif (@$log == 0) {
+	$ps->{summary} = 'empty commit message';
+    } else {
+	$ps->{summary} = $log->[0] . '...';
+    }
     $ps->{message} = join("\n",@$log);
     
     # skip Arch control files, unescape pika-escaped files