Add a patch to handle badly formed XLS files

lib/spreadsheet/excel/reader.rb

@@ -1309,6 +1309,15 @@ def set_row_address worksheet, work, pos, len
           xf = (flags & 0x0fff0000) >> 16
           attrs.store :default_format, @workbook.format(xf)
         end
+        # When a ROW record claims no cells (`first_used` == `first_unused`) but
+        # `set_missing_row_address` already recorded a valid offset from cell
+        # records found earlier in the stream, preserve the original offset.
+        # Some XLS writers emit ROW records after cell data with zeroed column
+        # ranges; without this fix, `read_row` would seek to the wrong position.
+        if first_used == first_unused && (existing = worksheet.row_addresses[index])
+          attrs[:offset] = existing[:offset]
+          attrs[:row_block] = existing[:row_block]
+        end
         # TODO: Row spacing
         worksheet.set_row_address index, attrs
       end

lib/spreadsheet/excel/worksheet.rb

@@ -12,7 +12,7 @@ class Worksheet < Spreadsheet::Worksheet
       include Spreadsheet::Excel::Offset
 
       offset :dimensions
-      attr_reader :offset, :ole, :links, :guts, :notes
+      attr_reader :offset, :ole, :links, :guts, :notes, :row_addresses
       def initialize opts = {}
         @row_addresses = nil
         super

test/integration.rb

@@ -1217,6 +1217,20 @@ def test_missing_row_op
       assert_not_nil sheet[2, 1]
     end
 
+    def test_row_record_with_empty_cell_range
+      # Some XLS writers emit ROW records with `first_used` == `first_unused` (claiming
+      # no cells) even though cell records (e.g. `LABELSST`) exist for that row
+      # earlier in the stream. Previously this caused `read_row` to seek to the wrong
+      # offset, returning an empty row despite valid cell data being present.
+      path = File.join @data, "test_row_record_empty_range.xls"
+      book = Spreadsheet.open path
+      sheet = book.worksheet 0
+      row0 = sheet.row(0).to_a.compact
+      assert_operator row0.length, :>, 0, "Row 0 should not be empty"
+      assert_equal "Name", row0[0]
+      assert_equal ["Name", "Code", "Description", "Reference", "Date", "Quantity"], row0
+    end
+
     def test_changes
       path = File.join @data, "test_changes.xls"
       book = Spreadsheet.open path