epub: Drop container xml objects upon error.

1 files changed, 60 insertions, 44 deletions

diff --git a/source/html/epub-doc.c b/source/html/epub-doc.c
index 0adab461..53976f78 100644
--- a/source/html/epub-doc.c
+++ b/source/html/epub-doc.c
@@ -385,8 +385,9 @@ static void
 epub_parse_header(fz_context *ctx, epub_document *doc)
 {
 	fz_archive *zip = doc->zip;
-	fz_buffer *buf;
-	fz_xml *container_xml, *content_opf;
+	fz_buffer *buf = NULL;
+	fz_xml *container_xml = NULL;
+	fz_xml *content_opf = NULL;
 	fz_xml *container, *rootfiles, *rootfile;
 	fz_xml *package, *manifest, *spine, *itemref, *metadata;
 	char base_uri[2048];
@@ -400,62 +401,77 @@ epub_parse_header(fz_context *ctx, epub_document *doc)
 	if (fz_has_archive_entry(ctx, zip, "META-INF/encryption.xml"))
 		fz_throw(ctx, FZ_ERROR_GENERIC, "EPUB is locked by DRM");
 
-	/* parse META-INF/container.xml to find OPF */
+	fz_var(buf);
+	fz_var(container_xml);
+	fz_var(content_opf);
 
-	buf = fz_read_archive_entry(ctx, zip, "META-INF/container.xml");
-	container_xml = fz_parse_xml(ctx, buf, 0);
-	fz_drop_buffer(ctx, buf);
+	fz_try(ctx)
+	{
+		/* parse META-INF/container.xml to find OPF */
 
-	container = fz_xml_find(container_xml, "container");
-	rootfiles = fz_xml_find_down(container, "rootfiles");
-	rootfile = fz_xml_find_down(rootfiles, "rootfile");
-	full_path = fz_xml_att(rootfile, "full-path");
-	if (!full_path)
-		fz_throw(ctx, FZ_ERROR_GENERIC, "cannot find root file in EPUB");
+		buf = fz_read_archive_entry(ctx, zip, "META-INF/container.xml");
+		container_xml = fz_parse_xml(ctx, buf, 0);
+		fz_drop_buffer(ctx, buf);
+		buf = NULL;
 
-	fz_dirname(base_uri, full_path, sizeof base_uri);
+		container = fz_xml_find(container_xml, "container");
+		rootfiles = fz_xml_find_down(container, "rootfiles");
+		rootfile = fz_xml_find_down(rootfiles, "rootfile");
+		full_path = fz_xml_att(rootfile, "full-path");
+		if (!full_path)
+			fz_throw(ctx, FZ_ERROR_GENERIC, "cannot find root file in EPUB");
 
-	/* parse OPF to find NCX and spine */
+		fz_dirname(base_uri, full_path, sizeof base_uri);
 
-	buf = fz_read_archive_entry(ctx, zip, full_path);
-	content_opf = fz_parse_xml(ctx, buf, 0);
-	fz_drop_buffer(ctx, buf);
+		/* parse OPF to find NCX and spine */
 
-	package = fz_xml_find(content_opf, "package");
-	version = fz_xml_att(package, "version");
-	if (!version || strcmp(version, "2.0"))
-		fz_warn(ctx, "unknown epub version: %s", version ? version : "<none>");
+		buf = fz_read_archive_entry(ctx, zip, full_path);
+		content_opf = fz_parse_xml(ctx, buf, 0);
+		fz_drop_buffer(ctx, buf);
+		buf = NULL;
 
-	metadata = fz_xml_find_down(package, "metadata");
-	if (metadata)
-	{
-		doc->dc_title = find_metadata(ctx, metadata, "title");
-		doc->dc_creator = find_metadata(ctx, metadata, "creator");
-	}
+		package = fz_xml_find(content_opf, "package");
+		version = fz_xml_att(package, "version");
+		if (!version || strcmp(version, "2.0"))
+			fz_warn(ctx, "unknown epub version: %s", version ? version : "<none>");
 
-	manifest = fz_xml_find_down(package, "manifest");
-	spine = fz_xml_find_down(package, "spine");
+		metadata = fz_xml_find_down(package, "metadata");
+		if (metadata)
+		{
+			doc->dc_title = find_metadata(ctx, metadata, "title");
+			doc->dc_creator = find_metadata(ctx, metadata, "creator");
+		}
 
-	if (path_from_idref(ncx, manifest, base_uri, fz_xml_att(spine, "toc"), sizeof ncx))
-	{
-		epub_parse_ncx(ctx, doc, ncx);
-	}
+		manifest = fz_xml_find_down(package, "manifest");
+		spine = fz_xml_find_down(package, "spine");
 
-	doc->spine = NULL;
-	tailp = &doc->spine;
-	itemref = fz_xml_find_down(spine, "itemref");
-	while (itemref)
-	{
-		if (path_from_idref(s, manifest, base_uri, fz_xml_att(itemref, "idref"), sizeof s))
+		if (path_from_idref(ncx, manifest, base_uri, fz_xml_att(spine, "toc"), sizeof ncx))
 		{
-			*tailp = epub_parse_chapter(ctx, doc, s);
-			tailp = &(*tailp)->next;
+			epub_parse_ncx(ctx, doc, ncx);
+		}
+
+		doc->spine = NULL;
+		tailp = &doc->spine;
+		itemref = fz_xml_find_down(spine, "itemref");
+		while (itemref)
+		{
+			if (path_from_idref(s, manifest, base_uri, fz_xml_att(itemref, "idref"), sizeof s))
+			{
+				*tailp = epub_parse_chapter(ctx, doc, s);
+				tailp = &(*tailp)->next;
+			}
+			itemref = fz_xml_find_next(itemref, "itemref");
 		}
-		itemref = fz_xml_find_next(itemref, "itemref");
 	}
+	fz_always(ctx)
+	{
+		fz_drop_xml(ctx, content_opf);
+		fz_drop_xml(ctx, container_xml);
+		fz_drop_buffer(ctx, buf);
+	}
+	fz_catch(ctx)
+		fz_rethrow(ctx);
 
-	fz_drop_xml(ctx, container_xml);
-	fz_drop_xml(ctx, content_opf);
 }
 
 static fz_outline *