git2spec.pl: handle empty merge commits

git2spec.pl

@@ -5,6 +5,8 @@ sub create_patches {
     my $pdir=shift;
     my $n=1;
     my @lines;
+    my $fname;
+    my $f=0;
 
     mkdir $pdir, 0755;
 
@@ -12,9 +14,13 @@ sub create_patches {
 
     while (<GIT>) {
         if (/^From [a-z0-9]{40} .*$/) {
-            my $fname = sprintf("%04d", $n++).".patch";
-            push @lines, $fname;
+            $fname = sprintf("%04d", $n++).".patch";
             open FH, ">".$pdir."/".$fname;
+            $f=1;
+        }
+        if (/^---$/ && $f == 1) {
+            push @lines, $fname;
+            $f=0;
         }
         print FH;
     }