ixml parser: a whitespace-only value is content, not formatting

src/ixml/cl_ixml.clas.locals_imp.abap

@@ -1303,6 +1303,7 @@ CLASS lcl_parser IMPLEMENTATION.
     DATA lv_xml        TYPE string.
     DATA lv_rest       TYPE string.
     DATA lv_whitespace TYPE string.
+    DATA lv_in_element TYPE abap_bool.
     DATA lv_bom        TYPE c LENGTH 1.
     DATA lv_offset    TYPE i.
     DATA lv_value     TYPE string.
@@ -1341,6 +1342,7 @@ CLASS lcl_parser IMPLEMENTATION.
         FIND FIRST OCCURRENCE OF '?>' IN lv_xml MATCH OFFSET lv_offset.
         ASSERT lv_offset > 0.
         lv_offset = lv_offset + 2.
+        lv_in_element = abap_false.
       ELSEIF lv_xml CP '<*'.
 * start or close tag
         FIND FIRST OCCURRENCE OF REGEX lc_regex_tag IN lv_xml RESULTS ls_match.
@@ -1354,6 +1356,7 @@ CLASS lcl_parser IMPLEMENTATION.
         IF lv_xml CP '</*'.
 * todo: check its the right name
           lo_parent ?= lo_parent->if_ixml_node~get_parent( ).
+          lv_in_element = abap_false.
         ELSE.
           CREATE OBJECT lo_node EXPORTING ii_parent = lo_parent.
           IF lv_name CA ':'.
@@ -1364,6 +1367,9 @@ CLASS lcl_parser IMPLEMENTATION.
 
           IF lv_tag NP '*/>'.
             lo_parent = lo_node.
+            lv_in_element = abap_true.
+          ELSE.
+            lv_in_element = abap_false.
           ENDIF.
         ENDIF.
 
@@ -1384,6 +1390,7 @@ CLASS lcl_parser IMPLEMENTATION.
         CREATE OBJECT lo_node EXPORTING ii_parent = lo_parent.
         lo_node->if_ixml_node~set_name( '#text' ).
         lo_node->if_ixml_node~set_value( lcl_escape=>unescape_value( lv_value ) ).
+        lv_in_element = abap_false.
       ENDIF.
 
       lv_xml = lv_xml+lv_offset.
@@ -1394,7 +1401,14 @@ CLASS lcl_parser IMPLEMENTATION.
       lv_rest = lv_xml.
       SHIFT lv_rest LEFT DELETING LEADING lv_whitespace.
       IF lv_rest IS INITIAL OR lv_rest(1) = '<'.
-        lv_xml = lv_rest.
+* whitespace that stands between a start tag and its own end tag is the
+* content of that element, `<FIELD> </FIELD>` carries a single blank, so it
+* is left for the value branch below - everything else is formatting
+        IF lv_in_element = abap_true AND lv_rest CP '</*' AND lv_rest <> lv_xml.
+          lv_in_element = abap_false.
+        ELSE.
+          lv_xml = lv_rest.
+        ENDIF.
       ENDIF.
     ENDWHILE.
 

src/ixml/cl_ixml.clas.testclasses.abap

@@ -17,6 +17,8 @@ CLASS ltcl_xml DEFINITION FOR TESTING RISK LEVEL HARMLESS DURATION SHORT FINAL.
     METHODS parse_basic FOR TESTING RAISING cx_static_check.
     METHODS root_element_after_crlf FOR TESTING RAISING cx_static_check.
     METHODS first_child_after_crlf FOR TESTING RAISING cx_static_check.
+    METHODS parse_blank_only_value FOR TESTING RAISING cx_static_check.
+    METHODS parse_indented_children FOR TESTING RAISING cx_static_check.
     METHODS parse_value_with_newline FOR TESTING RAISING cx_static_check.
     METHODS parse_bom FOR TESTING RAISING cx_static_check.
     METHODS parse_empty FOR TESTING RAISING cx_static_check.
@@ -474,6 +476,35 @@ CLASS ltcl_xml IMPLEMENTATION.
 
   ENDMETHOD.
 
+  METHOD parse_blank_only_value.
+
+    DATA li_root TYPE REF TO if_ixml_element.
+
+    li_root = parse( |<root><item> </item></root>| )->get_root_element( ).
+
+    cl_abap_unit_assert=>assert_equals(
+      act = li_root->get_first_child( )->get_value( )
+      exp = ` ` ).
+
+  ENDMETHOD.
+
+  METHOD parse_indented_children.
+
+    DATA li_root TYPE REF TO if_ixml_element.
+    DATA li_item TYPE REF TO if_ixml_node.
+
+    " whitespace between two tags stays formatting, the first child of root
+    " is the element and not a #text node
+    li_root = parse( |<root>\n  <item>A</item>\n</root>| )->get_root_element( ).
+
+    li_item = li_root->get_first_child( ).
+
+    cl_abap_unit_assert=>assert_equals(
+      act = li_item->get_name( )
+      exp = `item` ).
+
+  ENDMETHOD.
+
   METHOD parse_bom.
 
     DATA lv_bom  TYPE c LENGTH 1.

src/kernel/call_transformation/kernel_call_transformation.clas.testclasses.abap

@@ -96,6 +96,8 @@ CLASS ltcl_call_transformation DEFINITION FOR TESTING RISK LEVEL HARMLESS DURATI
     METHODS escape_char_data FOR TESTING RAISING cx_static_check.
     METHODS escape_char_data_roundtrip FOR TESTING RAISING cx_static_check.
     METHODS escape_entity_text_roundtrip FOR TESTING RAISING cx_static_check.
+    METHODS blank_only_roundtrip FOR TESTING RAISING cx_static_check.
+    METHODS newline_only_roundtrip FOR TESTING RAISING cx_static_check.
     METHODS newline_roundtrip FOR TESTING RAISING cx_static_check.
     METHODS to_string_simple FOR TESTING RAISING cx_static_check.
     METHODS to_string_empty FOR TESTING RAISING cx_static_check.
@@ -363,6 +365,55 @@ CLASS ltcl_call_transformation IMPLEMENTATION.
       exp = lv_exp ).
   ENDMETHOD.
 
+  METHOD blank_only_roundtrip.
+* a value of one blank is content, not formatting
+    DATA lv_xml TYPE string.
+    DATA: BEGIN OF ls_data,
+            field TYPE string,
+          END OF ls_data.
+
+    ls_data-field = ` `.
+
+    CALL TRANSFORMATION id
+      SOURCE data = ls_data
+      RESULT XML lv_xml.
+
+    CLEAR ls_data.
+
+    CALL TRANSFORMATION id
+      SOURCE XML lv_xml
+      RESULT data = ls_data.
+
+    cl_abap_unit_assert=>assert_equals(
+      act = ls_data-field
+      exp = ` ` ).
+  ENDMETHOD.
+
+  METHOD newline_only_roundtrip.
+    DATA lv_xml TYPE string.
+    DATA lv_exp TYPE string.
+    DATA: BEGIN OF ls_data,
+            field TYPE string,
+          END OF ls_data.
+
+    lv_exp = cl_abap_char_utilities=>newline.
+    ls_data-field = lv_exp.
+
+    CALL TRANSFORMATION id
+      SOURCE data = ls_data
+      RESULT XML lv_xml.
+
+    CLEAR ls_data.
+
+    CALL TRANSFORMATION id
+      SOURCE XML lv_xml
+      RESULT data = ls_data.
+
+    cl_abap_unit_assert=>assert_equals(
+      act = ls_data-field
+      exp = lv_exp ).
+  ENDMETHOD.
+
   METHOD convert_json_to_sxml.
     DATA lo_writer TYPE REF TO cl_sxml_string_writer.
     lo_writer = cl_sxml_string_writer=>create( ).