prune: do not prune beyond an optional base directory, and add a test

Previously, prune("wiki/srcdir/sandbox/test.mdwn") could delete srcdir
or even wiki, if they happened to be empty. This is rarely what you
want: there's usually some base directory (destdir, srcdir, transientdir
or another subdirectory of wikistatedir) beyond which you do not want to
delete.

1 files changed, 6 insertions, 5 deletions

diff --git a/IkiWiki/Render.pm b/IkiWiki/Render.pm
index d6c1f4f4c..a90d202ee 100644
--- a/IkiWiki/Render.pm
+++ b/IkiWiki/Render.pm
@@ -262,12 +262,13 @@ sub render ($$) {
 	}
 }
 
-sub prune ($) {
+sub prune ($;$) {
 	my $file=shift;
+	my $up_to=shift;
 
 	unlink($file);
 	my $dir=dirname($file);
-	while (rmdir($dir)) {
+	while ((! defined $up_to || $dir =~ m{^\Q$up_to\E\/}) && rmdir($dir)) {
 		$dir=dirname($dir);
 	}
 }
@@ -447,7 +448,7 @@ sub remove_del (@) {
 		}
 	
 		foreach my $old (@{$oldrenderedfiles{$page}}) {
-			prune($config{destdir}."/".$old);
+			prune($config{destdir}."/".$old, $config{destdir});
 		}
 
 		foreach my $source (keys %destsources) {
@@ -537,7 +538,7 @@ sub remove_unrendered () {
 		foreach my $file (@{$oldrenderedfiles{$page}}) {
 			if (! grep { $_ eq $file } @{$renderedfiles{$page}}) {
 				debug(sprintf(gettext("removing %s, no longer built by %s"), $file, $page));
-				prune($config{destdir}."/".$file);
+				prune($config{destdir}."/".$file, $config{destdir});
 			}
 		}
 	}
@@ -844,7 +845,7 @@ sub clean_rendered {
 	remove_unrendered();
 	foreach my $page (keys %oldrenderedfiles) {
 		foreach my $file (@{$oldrenderedfiles{$page}}) {
-			prune($config{destdir}."/".$file);
+			prune($config{destdir}."/".$file, $config{destdir});
 		}
 	}
 }