[tracker] tracker-extract: Protect all single valued properties in EPUB extractor

[Carlos Garnacho <carlosg src gnome org>]

commit f43e5dff8f7e0674acf0e8806e3f9b383fb14c66
Author: Carlos Garnacho <carlosg gnome org>
Date:   Mon Mar 14 01:03:46 2016 +0100

    tracker-extract: Protect all single valued properties in EPUB extractor
    
    In case of malformed documents or unexpected input, avoid creating sparql
    that will break cardinality constraints, warn nicely instead.

 src/tracker-extract/tracker-extract-epub.c |  103 +++++++++++++++++++++-------
 1 files changed, 79 insertions(+), 24 deletions(-)
---
diff --git a/src/tracker-extract/tracker-extract-epub.c b/src/tracker-extract/tracker-extract-epub.c
index e640f25..fef8012 100644
--- a/src/tracker-extract/tracker-extract-epub.c
+++ b/src/tracker-extract/tracker-extract-epub.c
@@ -49,12 +49,19 @@ typedef struct {
        gchar *graph;
        TrackerSparqlBuilder *preupdate;
        TrackerSparqlBuilder *metadata;
+       gchar *uri;
 
        OPFTagType element;
        GList *pages;
-       guint in_metadata : 1;
-       guint in_manifest : 1;
-       guint has_identifier : 1;
+       guint in_metadata         : 1;
+       guint in_manifest         : 1;
+       guint has_publisher       : 1;
+       guint has_title           : 1;
+       guint has_content_created : 1;
+       guint has_language        : 1;
+       guint has_subject         : 1;
+       guint has_description     : 1;
+       guint has_identifier      : 1;
        gchar *savedstring;
 } OPFData;
 
@@ -68,7 +75,9 @@ opf_data_new (TrackerExtractInfo *info)
 {
        OPFData *data = g_slice_new0 (OPFData);
        TrackerSparqlBuilder *builder;
+       GFile *file;
 
+       file = tracker_extract_info_get_file (info);
        builder = tracker_extract_info_get_preupdate_builder (info);
        data->preupdate = g_object_ref (builder);
 
@@ -76,6 +85,7 @@ opf_data_new (TrackerExtractInfo *info)
        data->metadata = g_object_ref (builder);
 
        data->graph = g_strdup (tracker_extract_info_get_graph (info));
+       data->uri = g_file_get_uri (file);
 
        return data;
 }
@@ -104,6 +114,7 @@ opf_data_free (OPFData *data)
        g_list_free (data->pages);
 
        g_free (data->graph);
+       g_free (data->uri);
 
        if (data->metadata) {
                g_object_unref (data->metadata);
@@ -274,15 +285,21 @@ opf_xml_text_handler (GMarkupParseContext   *context,
 
        switch (data->element) {
        case OPF_TAG_TYPE_PUBLISHER:
-               tracker_sparql_builder_predicate (data->metadata, "nco:publisher");
+               if (data->has_publisher) {
+                       g_warning ("Avoiding additional publisher (%s) in EPUB '%s'",
+                                  text, data->uri);
+               } else {
+                       data->has_publisher = TRUE;
+                       tracker_sparql_builder_predicate (data->metadata, "nco:publisher");
 
-               tracker_sparql_builder_object_blank_open (data->metadata);
-               tracker_sparql_builder_predicate (data->metadata, "a");
-               tracker_sparql_builder_object (data->metadata, "nco:Contact");
+                       tracker_sparql_builder_object_blank_open (data->metadata);
+                       tracker_sparql_builder_predicate (data->metadata, "a");
+                       tracker_sparql_builder_object (data->metadata, "nco:Contact");
 
-               tracker_sparql_builder_predicate (data->metadata, "nco:fullname");
-               tracker_sparql_builder_object_unvalidated (data->metadata, text);
-               tracker_sparql_builder_object_blank_close (data->metadata);
+                       tracker_sparql_builder_predicate (data->metadata, "nco:fullname");
+                       tracker_sparql_builder_object_unvalidated (data->metadata, text);
+                       tracker_sparql_builder_object_blank_close (data->metadata);
+               }
                break;
        case OPF_TAG_TYPE_AUTHOR:
        case OPF_TAG_TYPE_EDITOR:
@@ -381,7 +398,7 @@ opf_xml_text_handler (GMarkupParseContext   *context,
 
                if (data->element == OPF_TAG_TYPE_AUTHOR) {
                        role_str = "nco:creator";
-               } else if (data->element == OPF_TAG_TYPE_EDITOR) {
+               } else if (data->element == OPF_TAG_TYPE_EDITOR && !data->has_publisher) {
                        /* Should this be nco:contributor ?
                         * 'Editor' is a bit vague here.
                         */
@@ -448,32 +465,70 @@ opf_xml_text_handler (GMarkupParseContext   *context,
                break;
        }
        case OPF_TAG_TYPE_TITLE:
-               tracker_sparql_builder_predicate (data->metadata, "nie:title");
-               tracker_sparql_builder_object_unvalidated (data->metadata, text);
+               if (data->has_title) {
+                       g_warning ("Avoiding additional title (%s) in EPUB '%s'",
+                                  text, data->uri);
+               } else {
+                       data->has_title = TRUE;
+                       tracker_sparql_builder_predicate (data->metadata, "nie:title");
+                       tracker_sparql_builder_object_unvalidated (data->metadata, text);
+               }
                break;
        case OPF_TAG_TYPE_CREATED: {
-               gchar *date = tracker_date_guess (text);
+               if (data->has_content_created) {
+                       g_warning ("Avoiding additional creation time (%s) in EPUB '%s'",
+                                  text, data->uri);
+               } else {
+                       gchar *date = tracker_date_guess (text);
 
-               tracker_sparql_builder_predicate (data->metadata, "nie:contentCreated");
-               tracker_sparql_builder_object_unvalidated (data->metadata, date);
-               g_free (date);
+                       if (date) {
+                               data->has_content_created = TRUE;
+                               tracker_sparql_builder_predicate (data->metadata, "nie:contentCreated");
+                               tracker_sparql_builder_object_unvalidated (data->metadata, date);
+                               g_free (date);
+                       } else {
+                               g_warning ("Could not parse creation time (%s) in EPUB '%s'",
+                                          text, data->uri);
+                       }
+               }
                break;
        }
        case OPF_TAG_TYPE_LANGUAGE:
-               tracker_sparql_builder_predicate (data->metadata, "nie:language");
-               tracker_sparql_builder_object_unvalidated (data->metadata, text);
+               if (data->has_language) {
+                       g_warning ("Avoiding additional language (%s) in EPUB '%s'",
+                                  text, data->uri);
+               } else {
+                       data->has_language = TRUE;
+                       tracker_sparql_builder_predicate (data->metadata, "nie:language");
+                       tracker_sparql_builder_object_unvalidated (data->metadata, text);
+               }
                break;
        case OPF_TAG_TYPE_SUBJECT:
-               tracker_sparql_builder_predicate (data->metadata, "nie:subject");
-               tracker_sparql_builder_object_unvalidated (data->metadata, text);
+               if (data->has_subject) {
+                       g_warning ("Avoiding additional subject (%s) in EPUB '%s'",
+                                  text, data->uri);
+               } else {
+                       data->has_subject = TRUE;
+                       tracker_sparql_builder_predicate (data->metadata, "nie:subject");
+                       tracker_sparql_builder_object_unvalidated (data->metadata, text);
+               }
                break;
        case OPF_TAG_TYPE_DESCRIPTION:
-               tracker_sparql_builder_predicate (data->metadata, "nie:description");
-               tracker_sparql_builder_object_unvalidated (data->metadata, text);
+               if (data->has_description) {
+                       g_warning ("Avoiding additional description (%s) in EPUB '%s'",
+                                  text, data->uri);
+               } else {
+                       data->has_description = TRUE;
+                       tracker_sparql_builder_predicate (data->metadata, "nie:description");
+                       tracker_sparql_builder_object_unvalidated (data->metadata, text);
+               }
                break;
        case OPF_TAG_TYPE_UUID:
        case OPF_TAG_TYPE_ISBN:
-               if (!data->has_identifier) {
+               if (data->has_identifier) {
+                       g_warning ("Avoiding additional identifier (%s) in EPUB '%s'",
+                                  text, data->uri);
+               } else {
                        data->has_identifier = TRUE;
                        tracker_sparql_builder_predicate (data->metadata, "nie:identifier");
                        tracker_sparql_builder_object_unvalidated (data->metadata, text);