Bug 164913 - Calc opens slowly if all cells of a column are merged
Summary: Calc opens slowly if all cells of a column are merged
Status: NEW
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Calc (show other bugs)
Version:
(earliest affected)
24.8.4.2 release
Hardware: x86-64 (AMD64) All
: medium normal
Assignee: Not Assigned
URL:
Whiteboard:
Keywords: perf
Depends on:
Blocks: File-Opening
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Reported: 2025-01-29 07:16 UTC by ckakman
Modified: 2025-05-10 09:35 UTC (History)
2 users (show)

See Also:
Crash report or crash signature:

Attachments
An empty sheet with a single merged column (675.82 KB, application/vnd.oasis.opendocument.spreadsheet)
2025-01-29 07:17 UTC, ckakman 		Details
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Description ckakman 2025-01-29 07:16:10 UTC 
Description:
The title says it all.

I merged all cells of a column by selecting a column and clicking the merge button in the toolbar. Opening a Calc file with such a merged column is very, say 10x, slow.

Steps to Reproduce:
1. Select a column in Calc
2. Merge all cells of the selected column
3. Save in ODS format and reopen the file

Actual Results:
Very slow to open

Expected Results:
File opens in a couple of seconds.


Reproducible: Always


User Profile Reset: No

Additional Info:
I haven't tried on any platform other than Windows 10 and with Excel file formats.
Comment 1 ckakman 2025-01-29 07:17:11 UTC 
Created attachment 198843 [details]
An empty sheet with a single merged column
Comment 2 m_a_riosv 2025-01-29 11:21:49 UTC 
Yet slow, but quicker with
Version: 25.8.0.0.alpha0+ (X86_64) / LibreOffice Community
Build ID: a8ec21adf255b70bb6eeb0a1717190df303d8b26
CPU threads: 16; OS: Windows 11 X86_64 (build 26100); UI render: Skia/Vulkan; VCL: win
Locale: es-ES (es_ES); UI: en-US
Calc: CL threaded

It is a bit quicker opening with Excel.

Seems like a corner case.
Comment 3 Buovjaga 2025-05-10 09:35:58 UTC 
real    0m31,470s
user    0m32,839s
sys     0m0,172s

Arch Linux 64-bit
Version: 25.8.0.0.alpha0+ (X86_64) / LibreOffice Community
Build ID: 0d62ab61e982a0967386e40f21829fc95870b969
CPU threads: 8; OS: Linux 6.14; UI render: default; VCL: kf6 (cairo+wayland)
Locale: fi-FI (fi_FI.UTF-8); UI: en-US
Calc: CL threaded
Built on 10 May 2025