Unknown attribute 'ref' in parser::pop_element() for certain files

[MarioLiebisch]

This might be the same issue as reported in issue #433, but wanted to create a separate one just in case.

From my observations this seems to be triggered when cells were auto-populated by excel after dragging the corner of a cell (or multiple cells), i.e. doing this:

I've create two files that seem to be identical, but one was created by writing down the formulas by hand, while the other one was created dragging the first row down:

• working.xlsx (manually written)
• broken.xlsx (dragged cell down)

[tfussell]

Thanks for the detailed bug report. I'll try to work through it in the next few days.

[gamearea]

same problem

[beedaddy]

I'm having this issue, too (but since I only received the file, I don't know about auto-populated cells).

I get the error:

terminate called after throwing an instance of 'xml::parsing'
  what():  xl/worksheets/sheet1.xml:2:2206: error: unexpected attribute 'ref'

Example file:
broken2.xlsx

[sukoi26]

for broken2 the code xml for the cell at 2206 sheet1

<c r="A8" s="12"><f t="shared" ref="A8:A71" si="0">A7+1</f><v>3</v></c>
i suspect the level search element in xlx_consummer.cpp
level 1 is level 2 i does it parse the attributes map ?

[sukoi26]

to specify , never below in 2 level call parse attribute_map?

    int level = 1; // nesting level
        // 1 == <c>
        // 2 == <v>/<is>/<f>
        // exit loop at </c>
    while (level > 0)
    {
        xml::parser::event_type e = parser->next();
        switch (e)
        {
        case xml::parser::start_element: {
            ++level;
            break;
        }
        case xml::parser::end_element: {
            --level;
            break;
        }
        case xml::parser::characters: {
            // only want the characters inside one of the nested tags
            // without this a lot of formatting whitespace can get added
            if (level == 2)
            {
                // <v> -> numeric values
                // <is><t> -> inline string
                if (string_equal(parser->name(), "v"))
                {
                    c.value += std::move(parser->value());
                }
                 // <f> formula
                else if (string_equal(parser->name(), "f"))
                {
                    c.formula_string += std::move(parser->value());
                }
            }
            else if (level == 3)
            {
                // <is><t> -> inline string
                if (string_equal(parser->name(), "t"))
                {
                    c.value += std::move(parser->value());
                }
            }
            break;
        }
        case xml::parser::start_namespace_decl:
        case xml::parser::end_namespace_decl:
        case xml::parser::start_attribute:
        case xml::parser::end_attribute:
        case xml::parser::eof:
        default: {
            throw xlnt::exception("unexcpected XML parsing event");
        }
        }
    }

in second in libstudxml, the next() use pop()

  parser::event_type parser::
  next ()
  {
    if (state_ == state_next)
      return next_ (false);
    else
    {
      // If we previously peeked at start/end_element, then adjust
      // state accordingly.
      //
      switch (event_)
      {
      case end_element:
        {
          if (!element_state_.empty () &&
              element_state_.back ().depth == depth_)
            pop_element ();

          depth_--;
          break;
        }
      case start_element:
        {
          depth_++;
          break;
        }
      default:
        break;
      }

      state_ = state_next;
      return event_;
    }
  }

pop() in comment check attribute unhandled

  void parser::
  pop_element ()
  {
    // **Make sure there are no unhandled attributes left.**
    //
    const element_entry& e (element_state_.back ());
    if (e.attr_unhandled_ != 0)
    {
      // Find the first unhandled attribute and report it.
      //
      for (attribute_map_type::const_iterator i (e.attr_map_.begin ());
           i != e.attr_map_.end (); ++i)
      {
        if (!i->second.handled)
          throw parsing (
            *this, "unexpected attribute '" + i->first.string () + "'");
      }
      assert (false);
    }

    element_state_.pop_back ();
  }

So, it seem that in level2 something missing in parse <f> as

for (auto &attr : parser->attribute_map())
    {
        if (string_equal(attr.first.name(), "ref"))
        {
            c.ref = Cell_Formula_ Reference(row_arg, attr.second.value);
        }
...

[RockinRoel]

I've encountered a spreadsheet that has the same issue: https://eba.europa.eu/sites/default/documents/files/document_library/881117/EBA%20Validation%20Rules%20March%202020%20deactivation.xlsx

For now, I've worked around it by looping over, but ignoring, all attributes.

diff --git a/source/detail/serialization/xlsx_consumer.cpp b/source/detail/serialization/xlsx_consumer.cpp
index ea64b131..2898cbec 100644
--- a/source/detail/serialization/xlsx_consumer.cpp
+++ b/source/detail/serialization/xlsx_consumer.cpp
@@ -302,6 +302,9 @@ Cell parse_cell(xlnt::row_t row_arg, xml::parser *parser)
             throw xlnt::exception("unexcpected XML parsing event");
         }
         }
+        for (const auto &attr : parser->attribute_map()) {
+            (void)attr;
+        }
     }
     return c;
 }

[doomlaur]

I can confirm that this issue is present in xlnt v1.5.0 (latest stable release). However, compiling xlnt from the latest commit (currently 3a279fc from 2021-08-22) fixed this issue, so it seems that no fix is needed anymore.

[tfussell]

As reported above, this was fixed by ignoring extra attributes in 0ecad78. I've also just merged a PR (#647) which adds support for shared formulas which was the original trigger for this error. As a result, I'm going to close this old issue.