[tracker] Ignore strings that are either empty or all spaces for MP3 extraction

[Philip Van Hoof <pvanhoof src gnome org>]

commit a1c29967ac25b0c8dac97cab6eb0aba1ba6f5658
Author: Philip Van Hoof <philip codeminded be>
Date:   Tue Sep 8 15:42:07 2009 +0200

    Ignore strings that are either empty or all spaces for MP3 extraction

 src/libtracker-common/tracker-utils.c     |   20 +++++++++++++++++
 src/libtracker-common/tracker-utils.h     |    1 +
 src/tracker-extract/tracker-extract-mp3.c |   34 ++++++++++++++--------------
 3 files changed, 38 insertions(+), 17 deletions(-)
---
diff --git a/src/libtracker-common/tracker-utils.c b/src/libtracker-common/tracker-utils.c
index 051756c..ed4c4a5 100644
--- a/src/libtracker-common/tracker-utils.c
+++ b/src/libtracker-common/tracker-utils.c
@@ -33,6 +33,26 @@ tracker_is_empty_string (const char *str)
 	return str == NULL || str[0] == '\0';
 }
 
+inline gboolean
+tracker_is_blank_string (const char *str)
+{
+	register gint len, i;
+
+	if (str == NULL || str[0] == '\0') {
+		return TRUE;
+	}
+
+	len = strlen (str);
+
+	for (i = 0; i < len; i++) {
+		if (str[i] != ' ') {
+			return FALSE;
+		}
+	}
+
+	return TRUE;
+}
+
 /* Removes a substring modifing haystack in place */
 gchar *
 tracker_string_remove (gchar	   *haystack,
diff --git a/src/libtracker-common/tracker-utils.h b/src/libtracker-common/tracker-utils.h
index de8a518..fafd578 100644
--- a/src/libtracker-common/tracker-utils.h
+++ b/src/libtracker-common/tracker-utils.h
@@ -29,6 +29,7 @@
 #include <glib.h>
 
 gboolean tracker_is_empty_string            (const char  *str);
+gboolean tracker_is_blank_string            (const char  *str);
 gchar *  tracker_string_replace             (const gchar *haystack,
 					     const gchar *needle,
 					     const gchar *replacement);
diff --git a/src/tracker-extract/tracker-extract-mp3.c b/src/tracker-extract/tracker-extract-mp3.c
index 694ff91..faeccd2 100644
--- a/src/tracker-extract/tracker-extract-mp3.c
+++ b/src/tracker-extract/tracker-extract-mp3.c
@@ -1927,32 +1927,32 @@ extract_mp3 (const gchar *uri,
 	                                     filedata.id3v22_info.comment,
 	                                     filedata.id3v1_info.comment);
 
-	if (filedata.performer) {
+	if (!tracker_is_blank_string (filedata.performer)) {
 		filedata.performer_uri = tracker_uri_printf_escaped ("urn:artist:%s", filedata.performer);
 		tracker_sparql_builder_subject_iri (metadata, filedata.performer_uri);
 		tracker_sparql_builder_predicate (metadata, "a");
 		tracker_sparql_builder_object (metadata, "nmm:Artist");
 		tracker_sparql_builder_predicate (metadata, "nmm:artistName");
 		tracker_sparql_builder_object_unvalidated (metadata, filedata.performer);
-		g_free (filedata.performer);
 	}
+	g_free (filedata.performer);
 
-	if (filedata.album) {
+	if (!tracker_is_blank_string (filedata.album)) {
 		filedata.album_uri = tracker_uri_printf_escaped ("urn:album:%s", filedata.album);
 		tracker_sparql_builder_subject_iri (metadata, filedata.album_uri);
 		tracker_sparql_builder_predicate (metadata, "a");
 		tracker_sparql_builder_object (metadata, "nmm:MusicAlbum");
 		tracker_sparql_builder_predicate (metadata, "nmm:albumTitle");
 		tracker_sparql_builder_object_unvalidated (metadata, filedata.album);
-		g_free (filedata.album);
 	}
+	g_free (filedata.album);
 
 	tracker_sparql_builder_subject_iri (metadata, uri);
 	tracker_sparql_builder_predicate (metadata, "a");
 	tracker_sparql_builder_object (metadata, "nmm:MusicPiece");
 	tracker_sparql_builder_object (metadata, "nfo:Audio");
 
-	if (filedata.title) {
+	if (!tracker_is_blank_string (filedata.title)) {
 		tracker_sparql_builder_predicate (metadata, "nie:title");
 		tracker_sparql_builder_object_unvalidated (metadata, filedata.title);
 		/* do not delete title, needed by albumart */
@@ -1970,37 +1970,37 @@ extract_mp3 (const gchar *uri,
 		g_free (filedata.album_uri);
 	}
 
-	if (filedata.recording_time) {
+	if (!tracker_is_blank_string (filedata.recording_time)) {
 		tracker_sparql_builder_predicate (metadata, "nie:contentCreated");
 		tracker_sparql_builder_object_unvalidated (metadata, filedata.recording_time);
-		g_free (filedata.recording_time);
 	}
+	g_free (filedata.recording_time);
 
-	if (filedata.text) {
+	if (!tracker_is_blank_string (filedata.text)) {
 		tracker_sparql_builder_predicate (metadata, "nie:plainTextContent");
 		tracker_sparql_builder_object_unvalidated (metadata, filedata.text);
-		g_free (filedata.text);
 	}
+	g_free (filedata.text);
 
-	if (filedata.genre) {
+	if (!tracker_is_blank_string (filedata.genre)) {
 		tracker_sparql_builder_predicate (metadata, "nfo:genre");
 		tracker_sparql_builder_object_unvalidated (metadata, filedata.genre);
-		g_free (filedata.genre);
 	}
+	g_free (filedata.genre);
 
-	if (filedata.copyright) {
+	if (!tracker_is_blank_string (filedata.copyright)) {
 		tracker_sparql_builder_predicate (metadata, "nie:copyright");
 		tracker_sparql_builder_object_unvalidated (metadata, filedata.copyright);
-		g_free (filedata.copyright);
 	}
+	g_free (filedata.copyright);
 
-	if (filedata.comment) {
+	if (!tracker_is_blank_string (filedata.comment)) {
 		tracker_sparql_builder_predicate (metadata, "nie:comment");
 		tracker_sparql_builder_object_unvalidated (metadata, filedata.comment);
-		g_free (filedata.comment);
 	}
+	g_free (filedata.comment);
 
-	if (filedata.publisher) {
+	if (!tracker_is_blank_string (filedata.publisher)) {
 		tracker_sparql_builder_predicate (metadata, "nco:publisher");
 		tracker_sparql_builder_object_blank_open (metadata);
 		tracker_sparql_builder_predicate (metadata, "a");
@@ -2008,8 +2008,8 @@ extract_mp3 (const gchar *uri,
 		tracker_sparql_builder_predicate (metadata, "nco:fullname");
 		tracker_sparql_builder_object_unvalidated (metadata, filedata.publisher);
 		tracker_sparql_builder_object_blank_close (metadata);
-		g_free (filedata.publisher);
 	}
+	g_free (filedata.publisher);
 
 	/* Get mp3 stream info */
 	mp3_parse (buffer, buffer_size, audio_offset, uri, metadata, &filedata);