[PATCH] lib: provide _notmuch_database_log_append

[David Bremner]

_notmuch_database_log clears the log buffer each time. Rather than
introducing more complicated semantics about for this function, provide
a second function that does not clear the buffer. This is mainly a
convenience function for callers constructing complex or multi-line log
messages.

The changes to query.cc are to make sure that the common code path of
the new function is tested.
---
 lib/database.cc       | 16 ++++++++++++++++
 lib/notmuch-private.h |  4 ++++
 lib/query.cc          | 14 ++++++++------
 3 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/lib/database.cc b/lib/database.cc
index 66ee267..57a98c9 100644
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -383,6 +383,22 @@ _notmuch_database_log (notmuch_database_t *notmuch,
 	talloc_free (notmuch->status_string);
 
     notmuch->status_string = talloc_vasprintf (notmuch, format, va_args);
+    va_end (va_args);
+}
+
+void
+_notmuch_database_log_append (notmuch_database_t *notmuch,
+		      const char *format,
+		      ...)
+{
+    va_list va_args;
+
+    va_start (va_args, format);
+
+    if (notmuch->status_string)
+	notmuch->status_string = talloc_vasprintf_append (notmuch->status_string, format, va_args);
+    else
+	notmuch->status_string = talloc_vasprintf (notmuch, format, va_args);
 
     va_end (va_args);
 }
diff --git a/lib/notmuch-private.h b/lib/notmuch-private.h
index 3721431..643d9dd 100644
--- a/lib/notmuch-private.h
+++ b/lib/notmuch-private.h
@@ -196,6 +196,10 @@ void
 _notmuch_database_log (notmuch_database_t *notmuch,
 		       const char *format, ...);
 
+void
+_notmuch_database_log_append (notmuch_database_t *notmuch,
+			      const char *format, ...);
+
 unsigned long
 _notmuch_database_new_revision (notmuch_database_t *notmuch);
 
diff --git a/lib/query.cc b/lib/query.cc
index 7eb73a1..53efd4e 100644
--- a/lib/query.cc
+++ b/lib/query.cc
@@ -299,9 +299,10 @@ _notmuch_query_search_documents (notmuch_query_t *query,
 
     } catch (const Xapian::Error &error) {
 	_notmuch_database_log (notmuch,
-			       "A Xapian exception occurred performing query: %s\n"
+			       "A Xapian exception occurred performing query: %s\n",
+			       error.get_msg().c_str());
+	_notmuch_database_log_append (notmuch,
 			       "Query string was: %s\n",
-			       error.get_msg().c_str(),
 			       query->query_string);
 
 	notmuch->exception_reported = TRUE;
@@ -613,10 +614,11 @@ _notmuch_query_count_documents (notmuch_query_t *query, const char *type, unsign
 
     } catch (const Xapian::Error &error) {
 	_notmuch_database_log (notmuch,
-			       "A Xapian exception occurred performing query: %s\n"
-			       "Query string was: %s\n",
-			       error.get_msg().c_str(),
-			       query->query_string);
+			       "A Xapian exception occurred performing query: %s\n",
+			       error.get_msg().c_str());
+	_notmuch_database_log_append (notmuch,
+				      "Query string was: %s\n",
+				      query->query_string);
 	return NOTMUCH_STATUS_XAPIAN_EXCEPTION;
     }
 
-- 
2.8.1