[tracker] libtracker-data: Do not accept "... AS foo" anymore

[Carlos Garnacho <carlosg src gnome org>]

commit 7b6d8509613275bbb8d3715c050e875de8513aaf
Author: Carlos Garnacho <carlosg gnome org>
Date:   Tue Jul 11 00:52:38 2017 +0200

    libtracker-data: Do not accept "... AS foo" anymore
    
    Nowadays this is pretty useless nonstandard syntax, SPARQL1.1 settled on
    ".... AS ?foo" and we've accepted it for a long time.

 src/libtracker-data/tracker-sparql-expression.vala |   13 +++----------
 1 files changed, 3 insertions(+), 10 deletions(-)
---
diff --git a/src/libtracker-data/tracker-sparql-expression.vala 
b/src/libtracker-data/tracker-sparql-expression.vala
index 8b1b122..27b65a4 100644
--- a/src/libtracker-data/tracker-sparql-expression.vala
+++ b/src/libtracker-data/tracker-sparql-expression.vala
@@ -179,16 +179,9 @@ class Tracker.Sparql.Expression : Object {
                }
 
                if (accept (SparqlTokenType.AS)) {
-                       if (accept (SparqlTokenType.PN_PREFIX)) {
-                               // deprecated but supported for backward compatibility
-                               // (...) AS foo
-                               variable = context.get_variable (get_last_string ());
-                       } else {
-                               // syntax from SPARQL 1.1 Draft
-                               // (...) AS ?foo
-                               expect (SparqlTokenType.VAR);
-                               variable = context.get_variable (get_last_string ().substring (1));
-                       }
+                       // (...) AS ?foo
+                       expect (SparqlTokenType.VAR);
+                       variable = context.get_variable (get_last_string ().substring (1));
                        sql.append_printf (" AS %s", variable.sql_expression);
                        as_handled = true;