[tracker/wip/carlosg/sparql1.1: 59/113] libtracker-data: Use substring after SelectClause

[Carlos Garnacho <carlosg src gnome org>]

commit 525106dd8f30aa3f755c8622b2489602e6bf4c88
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 96b4a4380..dfe39c51f 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;