avoid internal error message when img uses just-deleted page

I think this used to be a fatal error, not just inline error, so I don't
know why it was never noticed, but if a page that an img directive mentions
gets deleted, bestlink() returns a file that no longer exists, and
srcfile() throws an error.

Note that bestlink's behavior of returning a deleted file could be
considered buggy. But, if it's changed to not do that, the page with the img
on it is not updated at all when the file is removed.

1 files changed, 7 insertions, 3 deletions

diff --git a/IkiWiki/Plugin/img.pm b/IkiWiki/Plugin/img.pm
index 17a9367d3..42de81bd1 100644
--- a/IkiWiki/Plugin/img.pm
+++ b/IkiWiki/Plugin/img.pm
@@ -41,6 +41,10 @@ sub preprocess (@) { #{{{
 	}
 
 	my $file = bestlink($params{page}, $image);
+	my $srcfile = srcfile($file, 1);
+	if (! defined $srcfile) {
+		error(sprintf(gettext("%s not found"), $image));
+	}
 
 	my $dir = $params{page};
 	my $base = IkiWiki::basename($file);
@@ -61,12 +65,12 @@ sub preprocess (@) { #{{{
 		
 		will_render($params{page}, $imglink);
 
-		if (-e $outfile && (-M srcfile($file) >= -M $outfile)) {
+		if (-e $outfile && (-M $srcfile >= -M $outfile)) {
 			$r = $im->Read($outfile);
 			error sprintf(gettext("failed to read %s: %s"), $outfile, $r) if $r;
 		}
 		else {
-			$r = $im->Read(srcfile($file));
+			$r = $im->Read($srcfile);
 			error sprintf(gettext("failed to read %s: %s"), $file, $r) if $r;
 
 			$r = $im->Resize(geometry => "${w}x${h}");
@@ -83,7 +87,7 @@ sub preprocess (@) { #{{{
 		}
 	}
 	else {
-		$r = $im->Read(srcfile($file));
+		$r = $im->Read($srcfile);
 		error sprintf(gettext("failed to read %s: %s"), $file, $r) if $r;
 		$imglink = $file;
 	}