[hotfix] serialize node sequence

Author: line-o

exist-core/src/main/java/org/exist/xquery/functions/fn/FunSerialize.java

@@ -144,32 +144,20 @@ public static Sequence normalize(final Expression callingExpr, final XQueryConte
         if (input.isEmpty())
             // "If the sequence that is input to serialization is empty, create a sequence S1 that consists of a zero-length string."
             {return StringValue.EMPTY_STRING;}
+        final String _separator = itemSeparator == null ? DEFAULT_ITEM_SEPARATOR : itemSeparator;
         final ValueSequence temp = new ValueSequence(input.getItemCount());
         for (final SequenceIterator i = input.iterate(); i.hasNext(); ) {
             final Item next = i.nextItem();
             if (Type.subTypeOf(next.getType(), Type.NODE)) {
                 if (next.getType() == Type.ATTRIBUTE || next.getType() == Type.NAMESPACE || next.getType() == Type.FUNCTION_REFERENCE)
                     {throw new XPathException(callingExpr, FnModule.SENR0001,
                         "It is an error if an item in the sequence to serialize is an attribute node or a namespace node.");}
-                if (itemSeparator != null && itemSeparator.length() > 0 && !temp.isEmpty()) {
-                    temp.add(new StringValue(itemSeparator + next.getStringValue()));
-                } else {
-                    temp.add(next);
-                }
+                temp.add(next);
             } else {
                 // atomic value
-                Item last = null;
-                if (!temp.isEmpty())
-                    {last = temp.itemAt(temp.getItemCount() - 1);}
-                if (last != null && last.getType() == Type.STRING)
-                    // "For each subsequence of adjacent strings in S2, copy a single string to the new sequence
-                    // equal to the values of the strings in the subsequence concatenated in order, each separated
-                    // by a single space."
-                    {((StringValue)last).append((itemSeparator == null ? " " : itemSeparator) + next.getStringValue());}
-                else
-                    // "For each item in S1, if the item is atomic, obtain the lexical representation of the item by
-                    // casting it to an xs:string and copy the string representation to the new sequence;"
-                    {temp.add(new StringValue(callingExpr, next.getStringValue()));}
+                // "For each item in S1, if the item is atomic, obtain the lexical representation of the item by
+                // casting it to an xs:string and copy the string representation to the new sequence;"
+                temp.add(new StringValue(callingExpr, next.getStringValue()));
             }
         }
 
@@ -184,6 +172,9 @@ public static Sequence normalize(final Expression callingExpr, final XQueryConte
                 } else {
                     receiver.characters(next.getStringValue());
                 }
+                if (i.hasNext()) {
+                    receiver.characters(_separator);
+                }
             }
             return (DocumentImpl)receiver.getDocument();
         } catch (final SAXException e) {

exist-core/src/test/xquery/xquery3/serialize.xql

@@ -927,3 +927,11 @@ function ser:serialize-html-5-needs-escape-elements() {
         => serialize($params)
         => normalize-space()
 };
+
+(: test for https://github.com/eXist-db/exist/issues/4702 :)
+declare
+    %test:assertEquals("<a>foo</a> <b>bar</b>")
+function ser:sequence-of-nodes() {
+    (<a>foo</a>, <b>bar</b>) => serialize()
+};
+