[tracker/rss-enclosures] libtracker-db: Fixed a problem with sqlite3_interrupt usage

[Roberto Guido <rguido src gnome org>]

commit 834c931a24ce7d65eaaeca7e31d5ac34f5b373fc
Author: Philip Van Hoof <philip codeminded be>
Date:   Thu Apr 22 16:09:37 2010 +0200

    libtracker-db: Fixed a problem with sqlite3_interrupt usage

 src/libtracker-db/tracker-db-interface-sqlite.c |   29 ++++++++++++++++++++--
 1 files changed, 26 insertions(+), 3 deletions(-)
---
diff --git a/src/libtracker-db/tracker-db-interface-sqlite.c b/src/libtracker-db/tracker-db-interface-sqlite.c
index 56710dc..c063ae3 100644
--- a/src/libtracker-db/tracker-db-interface-sqlite.c
+++ b/src/libtracker-db/tracker-db-interface-sqlite.c
@@ -669,17 +669,40 @@ create_result_set_from_stmt (TrackerDBInterfaceSqlite  *interface,
 	TrackerDBInterfaceSqlitePrivate *priv;
 	TrackerDBResultSet *result_set = NULL;
 	gint columns, result;
+	gboolean interrupted = FALSE;
 
 	priv = TRACKER_DB_INTERFACE_SQLITE_GET_PRIVATE (interface);
 	columns = sqlite3_column_count (stmt);
 	result = SQLITE_OK;
 
 	while (result == SQLITE_OK  ||
-	       result == SQLITE_ROW) {
+	       result == SQLITE_ROW ||
+	       result == SQLITE_INTERRUPT) {
 
 		result = sqlite3_step (stmt);
 
 		switch (result) {
+		case SQLITE_INTERRUPT:
+
+			/* Apparently it's not sufficient that you sqlite3_reset a stmt
+			 * once it got interrupted. Apparently you need to continue reading
+			 * it using sqlite3_step() until that returns SQLITE_OK.
+			 *
+			 * A way to reproduce this issue is by using tracker-search with a
+			 * query that matches at least one resource. Then set a break point
+			 * in gdb on fulltextFilter. When the breakpoint hits, wait for a 
+			 * minute for watchdog_cb to happen. When you cont this case should
+			 * happen here. Without the SQLITE_INTERRUPT in the while expression
+			 * above sqlite3_reset() would be the only thing that happens (like
+			 * the case of SQLITE_ERROR). But then the stmt is left in such a
+			 * state that each subsequent use of it immediately returns the 
+			 * SQLITE_INTERRUPT again. If we "read-away" the stmt with
+			 * sqlite3_step(), then this doesn't happen.
+			 **/
+
+			sqlite3_reset (stmt);
+			interrupted = TRUE;
+			break;
 		case SQLITE_ERROR:
 			sqlite3_reset (stmt);
 			break;
@@ -695,7 +718,7 @@ create_result_set_from_stmt (TrackerDBInterfaceSqlite  *interface,
 		}
 	}
 
-	if (result != SQLITE_DONE) {
+	if (result != SQLITE_DONE || interrupted) {
 		g_hash_table_foreach (priv->statements, foreach_print_error, stmt);
 
 		/* This is rather fatal */
@@ -727,7 +750,7 @@ create_result_set_from_stmt (TrackerDBInterfaceSqlite  *interface,
 			             TRACKER_DB_INTERFACE_ERROR,
 			             TRACKER_DB_QUERY_ERROR,
 			             "%s",
-			             sqlite3_errmsg (priv->db));
+			             interrupted ? "Interrupted" : sqlite3_errmsg (priv->db));
 		}
 
 		/* If there was an error, result set may be invalid or incomplete */