There is no way to exit the chart editing dialogue, Data Ranges, after making a selection, without the chart being updated with the new selection. It doesn't matter whether the OK, Cancel or Close (X) button is clicked, or the dialogue is closed by means of the Escape key, the newly selected, potentially erroneous data range appears on the chart, and there is no undo function that reverses the action.
Steps to Reproduce:
1.) Double-click a chart to edit it.
2.) Right-click the chart and select Data Ranges...
3.) On the Data Series tab, click the minimize icon next to the Categories field.
4.) Select any cell range.
5.) Close the Data Ranges dialogue by any means possible.
The cell range selected above becomes the range applied to the chart, regardless of the operation being canceled. No undo option is able to reverse the selection and revert to chart to its original content.
On clicking OK, one would expect the desired changes to be implemented. However, selecting Cancel, Close (X), or hitting Escape, should close the editing dialogue without performing any changes to the chart. In any case, clicking Undo should revert the chart to its pre-edited state.
User Profile Reset: No
This process was tested using LibreOffice 126.96.36.199 on Linux Mint 17.3 64-bit, and LibreOffice 188.8.131.52 on Windows 7 64-bit. Locale is en_ZA.
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:49.0) Gecko/20100101 Firefox/49.0
Known problem: currently chart edits are not undoable via ctrl+Z.
See bug 62595.
Best regards. JBF
*** This bug has been marked as a duplicate of bug 62595 ***