lobugs

README.md

@@ -7,6 +7,7 @@ Various spreadsheet file format notes.
 - [XLSB Short Records](/xlsb_short_records/README.md)
 - [Number Formats](/ssf/README.md)
 - [SpreadsheetML2003](/xlml/README.md)
+- [LibreOffice Bugs](/lobugs/README.md)
 
 Project sponsored by [SheetJS](https://sheetjs.com)
 

lobugs/README.md

@@ -0,0 +1,39 @@
+# LibreOffice Bugs
+
+## Rounding and "ulp" errors
+
+[Original SheetJS Bug Report](https://github.com/SheetJS/sheetjs/issues/1814)
+
+[Original LO Bug Report](https://bugs.documentfoundation.org/show_bug.cgi?id=83511)
+
+Excel will write the full IEEE754 value.  This affects values like `0.1 + 0.2`
+which have stored values like `0.30000000000000004`.  Excel "General" formatting
+is strategically chosen to cap at 11 digits, avoiding these issues in display.
+
+LibreOffice rounds off the last few digits.
+
+The following files are referenced in the issues:
+
+- [Original issue file](./xls_issue_49.xls)
+- [File Resaved in Excel 2011](./xls_issue_49_2011.xlsx) 
+- [File Resaved in Excel 2013](./xls_issue_49_2013.xlsx)
+- [File Resaved in Excel 2013 "Strict OpenXML"](./xls_issue_49_2011_strict.xlsx)
+- [File Resaved in LibreOffice](./xls_issue_49_libreoffice.xlsx)
+
+Look at cell C172 in the sheet1.xml subfile of each.  The Excel files show:
+
+```xml
+      <c r="C172" s="1">
+        <v>3.2400000000000005E-2</v>
+      </c>
+```
+
+The LO file shows:
+
+```xml
+      <c r="C172" s="4" t="n">
+        <v>0.0324</v>
+      </c>
+```
+
+[![Analytics](https://ga-beacon.appspot.com/UA-36810333-1/SheetJS/notes?pixel)](https://github.com/SheetJS/notes)