Created attachment 203851 [details]
file with incorrect chart

Description:
When importing PPTX files with charts containing mixed data formats, LibreOffice Impress incorrectly renders time values by ignoring cell-specific format codes and applying only the general format to all data points.

Steps to Reproduce:

Create a chart in Microsoft PowerPoint with mixed time formats:

Most cells formatted as "h:mm"

Some individual cells formatted as "[h]:mm:ss"

Save the presentation as PPTX

Open the file in LibreOffice Impress

Observe the chart rendering

Expected Result:

Cell with value 2.206 and formatCode="[h]:mm:ss;@" should display as 52:56:38

Other cells with general h:mm format should display accordingly

Actual Result:

All cells are rendered using the general <c:formatCode>h:mm;@</c:formatCode>

Value 2.206 incorrectly displays as 4:56 instead of 52:56:38

Cell-specific <c:pt formatCode="..."> attributes are completely ignored

How it looks in xml chart:
<c:numRef>
    <c:f>Лист1!$B$2:$B$4</c:f>
    <c:numCache>
        <c:formatCode>h:mm;@</c:formatCode>
        <c:ptCount val="3"/>
        <c:pt idx="0">
            <c:v>0.59699999999999998</c:v>
        </c:pt>
        <c:pt idx="1">
            <c:v>0.72</c:v>
        </c:pt>
        <c:pt idx="2" formatCode="[h]:mm:ss;@">
            <c:v>2.206</c:v>
        </c:pt>
    </c:numCache>
</c:numRef>