Iterate Over the Items (Not the Operands) of a Literal Sequence

The current code iterates over the (empty) list of operands of a Literal
Sequence, ignoring any items in it, so Literal Sequences are always
ignored in the ExpressionSequence.

Task-number: QTBUG-35897
Change-Id: I60341ac21c8e3b77bf6d8dfeebdbafe010844406
Reviewed-by: Erik Verbruggen <erik.verbruggen@theqtcompany.com>

3 files changed, 16 insertions, 2 deletions

diff --git a/src/xmlpatterns/expr/qexpression_p.h b/src/xmlpatterns/expr/qexpression_p.h
index c799725..7a7899f 100644
--- a/src/xmlpatterns/expr/qexpression_p.h
+++ b/src/xmlpatterns/expr/qexpression_p.h
@@ -375,11 +375,16 @@ namespace QPatternist
             IDExistsFN,
 
             /**
-             * Identifies ExpressionSequence and LiteralSequence.
+             * Identifies ExpressionSequence.
              */
             IDExpressionSequence,
 
             /**
+             * Identifies LiteralSequence.
+             */
+            IDLiteralSequence,
+
+            /**
              * Identifies GeneralComparison.
              */
             IDGeneralComparison,
diff --git a/src/xmlpatterns/expr/qexpressionsequence.cpp b/src/xmlpatterns/expr/qexpressionsequence.cpp
index 4ff8082..c71beb9 100644
--- a/src/xmlpatterns/expr/qexpressionsequence.cpp
+++ b/src/xmlpatterns/expr/qexpressionsequence.cpp
@@ -34,6 +34,8 @@
 #include "qcardinalityverifier_p.h"
 #include "qcommonsequencetypes_p.h"
 #include "qemptysequence_p.h"
+#include "qabstractxmlforwarditerator_p.h"
+#include "qliteral_p.h"
 #include "qsequencemappingiterator_p.h"
 
 #include "qexpressionsequence_p.h"
@@ -106,6 +108,13 @@ Expression::Ptr ExpressionSequence::compress(const StaticContext::Ptr &context)
 
             for(; seqIt != seqEnd; ++seqIt)
                 result.append(*seqIt);
+        } else if (Id == IDLiteralSequence) {
+            /* Rewrite "(1, (2, 3), 4)" into "(1, 2, 3, 4)" */
+            // Note: LiteralSequence does not use the dynamic context, so we pass in a nullptr.
+            Item::Iterator::Ptr seqIt = (*it)->evaluateSequence(DynamicContext::Ptr(Q_NULLPTR));
+
+            while (!seqIt->next().isNull())
+                result.append(Literal::Ptr(new Literal(seqIt->current())));
         }
         else
             result.append(*it);
diff --git a/src/xmlpatterns/expr/qliteralsequence.cpp b/src/xmlpatterns/expr/qliteralsequence.cpp
index e0b610d..8c920d3 100644
--- a/src/xmlpatterns/expr/qliteralsequence.cpp
+++ b/src/xmlpatterns/expr/qliteralsequence.cpp
@@ -73,7 +73,7 @@ ExpressionVisitorResult::Ptr LiteralSequence::accept(const ExpressionVisitor::Pt
 
 Expression::ID LiteralSequence::id() const
 {
-    return IDExpressionSequence;
+    return IDLiteralSequence;
 }
 
 Expression::Properties LiteralSequence::properties() const