[tracker/wip/carlosg/sparql1.1: 102/145] libtracker-data: Use substring after SelectClause

[Carlos Garnacho <carlosg src gnome org>]

commit 7386585461f5fa2f095a3f39b6da1a96c7f7312c
Author: Carlos Garnacho <carlosg gnome org>
Date:   Wed Jun 19 00:57:59 2019 +0200

    libtracker-data: Use substring after SelectClause
    
    And ensure SolutionModifier is part of it. We still may project variables
    from the GROUP BY into the select clause, so we must ensure we can still
    propagate the variables up.

 src/libtracker-data/tracker-sparql.c | 33 ++++++++++++++++++++++++---------
 1 file changed, 24 insertions(+), 9 deletions(-)
---
diff --git a/src/libtracker-data/tracker-sparql.c b/src/libtracker-data/tracker-sparql.c
index edbce4f44..89fcb0327 100644
--- a/src/libtracker-data/tracker-sparql.c
+++ b/src/libtracker-data/tracker-sparql.c
@@ -2057,13 +2057,15 @@ translate_SelectQuery (TrackerSparql  *sparql,
                        GError        **error)
 {
        TrackerParserNode *select_clause;
-       TrackerStringBuilder *str;
+       TrackerStringBuilder *select, *str, *old;
 
        /* SelectQuery ::= SelectClause DatasetClause* WhereClause SolutionModifier
         */
 
        /* Skip select clause here */
+       select = _append_placeholder (sparql);
        str = _append_placeholder (sparql);
+       old = tracker_sparql_swap_builder (sparql, str);
        select_clause = _skip_rule (sparql, NAMED_RULE_SelectClause);
 
        while (_check_in_rule (sparql, NAMED_RULE_DatasetClause)) {
@@ -2075,14 +2077,16 @@ translate_SelectQuery (TrackerSparql  *sparql,
        if (!_check_undefined_variables (sparql, TRACKER_SELECT_CONTEXT (sparql->context), error))
                return FALSE;
 
+       _call_rule (sparql, NAMED_RULE_SolutionModifier, error);
+
+       tracker_sparql_swap_builder (sparql, old);
+
        /* Now that we have all variable/binding information available,
         * process the select clause.
         */
-       if (!_postprocess_rule (sparql, select_clause, str, error))
+       if (!_postprocess_rule (sparql, select_clause, select, error))
                return FALSE;
 
-       _call_rule (sparql, NAMED_RULE_SolutionModifier, error);
-
        return TRUE;
 }
 
@@ -2091,7 +2095,7 @@ translate_SubSelect (TrackerSparql  *sparql,
                      GError        **error)
 {
        TrackerContext *context, *prev;
-       TrackerStringBuilder *str;
+       TrackerStringBuilder *select, *str, *old;
        TrackerParserNode *select_clause;
 
        /* SubSelect ::= SelectClause WhereClause SolutionModifier ValuesClause
@@ -2102,20 +2106,25 @@ translate_SubSelect (TrackerSparql  *sparql,
        tracker_sparql_push_context (sparql, context);
 
        /* Skip select clause here */
+       select = _append_placeholder (sparql);
        str = _append_placeholder (sparql);
+       old = tracker_sparql_swap_builder (sparql, str);
+
        select_clause = _skip_rule (sparql, NAMED_RULE_SelectClause);
 
        _call_rule (sparql, NAMED_RULE_WhereClause, error);
 
+       _call_rule (sparql, NAMED_RULE_SolutionModifier, error);
+       _call_rule (sparql, NAMED_RULE_ValuesClause, error);
+
+       tracker_sparql_swap_builder (sparql, old);
+
        /* Now that we have all variable/binding information available,
         * process the select clause.
         */
-       if (!_postprocess_rule (sparql, select_clause, str, error))
+       if (!_postprocess_rule (sparql, select_clause, select, error))
                return FALSE;
 
-       _call_rule (sparql, NAMED_RULE_SolutionModifier, error);
-       _call_rule (sparql, NAMED_RULE_ValuesClause, error);
-
        sparql->current_state.expression_type = TRACKER_SELECT_CONTEXT (context)->type;
        tracker_sparql_pop_context (sparql, FALSE);
        sparql->current_state.select_context = prev;
@@ -2258,6 +2267,8 @@ static gboolean
 translate_AskQuery (TrackerSparql  *sparql,
                     GError        **error)
 {
+       TrackerStringBuilder *str, *old;
+
        /* AskQuery ::= 'ASK' DatasetClause* WhereClause SolutionModifier
         */
        _expect (sparql, RULE_TYPE_LITERAL, LITERAL_ASK);
@@ -2268,9 +2279,13 @@ translate_AskQuery (TrackerSparql  *sparql,
                _call_rule (sparql, NAMED_RULE_DatasetClause, error);
        }
 
+       str = _append_placeholder (sparql);
+       old = tracker_sparql_swap_builder (sparql, str);
        _call_rule (sparql, NAMED_RULE_WhereClause, error);
        _call_rule (sparql, NAMED_RULE_SolutionModifier, error);
 
+       tracker_sparql_swap_builder (sparql, old);
+
        _append_string (sparql, ") WHEN 1 THEN 'true' WHEN 0 THEN 'false' ELSE NULL END");
 
        return TRUE;