fix(grid): collapsed column group calcPixelWidth incorrectly constrained to minColumnWidth (#17042)

[Copilot]

When a collapsible column group is collapsed and its visible child columns have explicit widths smaller than minColumnWidth (136px), the header and cell virtual scrollers use mismatched widths — causing horizontal misalignment after scrolling.

Root cause

PR #16636 added a minColumnWidth floor in getConstrainedSizePx() targeting unsized columns. Column groups have widthSetByUser = false (their set width() is a no-op) so this condition also fired for them. With one visible collapsed child at 100px:

• Header scroller: group.calcPixelWidth = 136 ← incorrectly floored
• Cell scroller: columnA.calcPixelWidth = 100 ← correct explicit width
• Result: 36px misalignment offset accumulates past the group boundary

Fix

Added !this.columnGroup guard to the new condition in getConstrainedSizePx(). Column group width is always the sum of visible children — it must never be independently floored to minColumnWidth.

- } else if (!this.minWidth && (!this.widthSetByUser || this.width === 'fit-content')
+ } else if (!this.minWidth && !this.columnGroup && (!this.widthSetByUser || this.width === 'fit-content')
      && !this.grid.columnWidthSetByUser && (!newSize || newSize <= this.grid.minColumnWidth)) {

Changes

• column.component.ts — One-line guard added to getConstrainedSizePx()
• grid-collapsible-columns.spec.ts — Regression test: collapsed group calcPixelWidth must equal the sum of its visible children's widths, not minColumnWidth
• test-utils/grid-samples.spec.ts — CollapsibleGroupFirstColumnWidthComponent fixture (collapsible first group, explicit child widths < 136px, standalone columns with explicit widths forcing a horizontal scrollbar)
• CHANGELOG.md — Bug fix entry under 21.2.0

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• accounts.google.com
  • Triggering command: /proc/self/exe /proc/self/exe --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=network --no-sandbox --disable-dev-shm-usage --use-angle=swiftshader-webgl --crashpad-handler-pid=4858 --enable-crash-reporter=, --noerrdialogs --user-data-dir=/tmp/karma-5380339 --change-stack-guard-on-fork=enable --shared-files=network_parent_dirs_pipe:100,v8_context_snapshot_data:101 --field-trial-handle=3,i,1767742148619126290,4177245314570888366,262144 --disable-features=PaintHolding --variations-seed-version --trace-process-track-uuid=3190708989122997041 (dns block)
  • Triggering command: /home/REDACTED/.cache/puppeteer/chrome/linux-145.0.7632.46/chrome-linux64/chrome /home/REDACTED/.cache/puppeteer/chrome/linux-145.0.7632.46/chrome-linux64/chrome --user-data-dir=/tmp/karma-5380339 --enable-automation --no-default-browser-check --no-first-run --disable-default-apps --disable-popup-blocking --disable-translate --disable-REDACTED-timer-throttling --disable-renderer-REDACTEDing --disable-device-discovery-notifications --no-sandbox --disable-gpu --window-size=820,800 --js-flags=--expose-gc http://localhost:9876/?id=5380339 --headless --disable-gpu --disable-dev-shm-usage --remote-debugging-port=9222 (dns block)
  • Triggering command: /proc/self/exe /proc/self/exe --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=network --no-sandbox --disable-dev-shm-usage --use-angle=swiftshader-webgl --crashpad-handler-pid=4859 --enable-crash-reporter=, --noerrdialogs --user-data-dir=/tmp/karma-92561409 --change-stack-guard-on-fork=enable --shared-files=network_parent_dirs_pipe:100,v8_context_snapshot_data:101 --field-trial-handle=3,i,10303362430134108348,5035785990288150114,262144 --disable-features=PaintHolding --variations-seed-version --trace-process-track-uuid=3190708989122997041 (dns block)
• clients2.google.com
  • Triggering command: /proc/self/exe /proc/self/exe --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=network --no-sandbox --disable-dev-shm-usage --use-angle=swiftshader-webgl --crashpad-handler-pid=4858 --enable-crash-reporter=, --noerrdialogs --user-data-dir=/tmp/karma-5380339 --change-stack-guard-on-fork=enable --shared-files=network_parent_dirs_pipe:100,v8_context_snapshot_data:101 --field-trial-handle=3,i,1767742148619126290,4177245314570888366,262144 --disable-features=PaintHolding --variations-seed-version --trace-process-track-uuid=3190708989122997041 (dns block)
  • Triggering command: /proc/self/exe /proc/self/exe --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=network --no-sandbox --disable-dev-shm-usage --use-angle=swiftshader-webgl --crashpad-handler-pid=4859 --enable-crash-reporter=, --noerrdialogs --user-data-dir=/tmp/karma-92561409 --change-stack-guard-on-fork=enable --shared-files=network_parent_dirs_pipe:100,v8_context_snapshot_data:101 --field-trial-handle=3,i,10303362430134108348,5035785990288150114,262144 --disable-features=PaintHolding --variations-seed-version --trace-process-track-uuid=3190708989122997041 (dns block)
  • Triggering command: /home/REDACTED/.cache/puppeteer/chrome/linux-145.0.7632.46/chrome-linux64/chrome /home/REDACTED/.cache/puppeteer/chrome/linux-145.0.7632.46/chrome-linux64/chrome --user-data-dir=/tmp/karma-5380339 --enable-automation --no-default-browser-check --no-first-run --disable-default-apps --disable-popup-blocking --disable-translate --disable-REDACTED-timer-throttling --disable-renderer-REDACTEDing --disable-device-discovery-notifications --no-sandbox --disable-gpu --window-size=820,800 --js-flags=--expose-gc http://localhost:9876/?id=5380339 --headless --disable-gpu --disable-dev-shm-usage --remote-debugging-port=9222 (dns block)
• content-autofill.googleapis.com
  • Triggering command: /proc/self/exe /proc/self/exe --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=network --no-sandbox --disable-dev-shm-usage --use-angle=swiftshader-webgl --crashpad-handler-pid=5588 --enable-crash-reporter=, --noerrdialogs --user-data-dir=/tmp/karma-2736915 --change-stack-guard-on-fork=enable --shared-files=network_parent_dirs_pipe:100,v8_context_snapshot_data:101 --field-trial-handle=3,i,3113948546176594774,5895901476528518885,262144 --disable-features=PaintHolding --variations-seed-version --trace-process-track-uuid=3190708989122997041 sources.ts es.ts (dns block)
  • Triggering command: /home/REDACTED/.cache/puppeteer/chrome/linux-145.0.7632.46/chrome-linux64/chrome /home/REDACTED/.cache/puppeteer/chrome/linux-145.0.7632.46/chrome-linux64/chrome --user-data-dir=/tmp/karma-2736915 --enable-automation --no-default-browser-check --no-first-run --disable-default-apps --disable-popup-blocking --disable-translate --disable-REDACTED-timer-throttling --disable-renderer-REDACTEDing --disable-device-discovery-notifications --no-sandbox --disable-gpu --window-size=820,800 --js-flags=--expose-gc http://localhost:9876/?id=2736915 --headless --disable-gpu --disable-dev-shm-usage --remote-debugging-port=9222 (dns block)
  • Triggering command: /proc/self/exe /proc/self/exe --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=network --no-sandbox --disable-dev-shm-usage --use-angle=swiftshader-webgl --crashpad-handler-pid=5937 --enable-crash-reporter=, --noerrdialogs --user-data-dir=/tmp/karma-98524574 --change-stack-guard-on-fork=enable --shared-files=network_parent_dirs_pipe:100,v8_context_snapshot_data:101 --field-trial-handle=3,i,6781892557428214697,16982997161804983729,262144 --disable-features=PaintHolding --variations-seed-version --trace-process-track-uuid=3190708989122997041 (dns block)
• redirector.gvt1.com
  • Triggering command: /proc/self/exe /proc/self/exe --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=network --no-sandbox --disable-dev-shm-usage --use-angle=swiftshader-webgl --crashpad-handler-pid=4859 --enable-crash-reporter=, --noerrdialogs --user-data-dir=/tmp/karma-92561409 --change-stack-guard-on-fork=enable --shared-files=network_parent_dirs_pipe:100,v8_context_snapshot_data:101 --field-trial-handle=3,i,10303362430134108348,5035785990288150114,262144 --disable-features=PaintHolding --variations-seed-version --trace-process-track-uuid=3190708989122997041 (dns block)
  • Triggering command: /proc/self/exe /proc/self/exe --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=network --no-sandbox --disable-dev-shm-usage --use-angle=swiftshader-webgl --crashpad-handler-pid=4858 --enable-crash-reporter=, --noerrdialogs --user-data-dir=/tmp/karma-5380339 --change-stack-guard-on-fork=enable --shared-files=network_parent_dirs_pipe:100,v8_context_snapshot_data:101 --field-trial-handle=3,i,1767742148619126290,4177245314570888366,262144 --disable-features=PaintHolding --variations-seed-version --trace-process-track-uuid=3190708989122997041 (dns block)
  • Triggering command: /home/REDACTED/.cache/puppeteer/chrome/linux-145.0.7632.46/chrome-linux64/chrome /home/REDACTED/.cache/puppeteer/chrome/linux-145.0.7632.46/chrome-linux64/chrome --user-data-dir=/tmp/karma-92561409 --enable-automation --no-default-browser-check --no-first-run --disable-default-apps --disable-popup-blocking --disable-translate --disable-REDACTED-timer-throttling --disable-renderer-REDACTEDing --disable-device-discovery-notifications --no-sandbox --disable-gpu --window-size=820,800 --js-flags=--expose-gc http://localhost:9876/?id=92561409 --headless --disable-gpu --disable-dev-shm-usage --remote-debugging-port=9222 (dns block)
• www.google.com
  • Triggering command: /proc/self/exe /proc/self/exe --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=network --no-sandbox --disable-dev-shm-usage --use-angle=swiftshader-webgl --crashpad-handler-pid=4858 --enable-crash-reporter=, --noerrdialogs --user-data-dir=/tmp/karma-5380339 --change-stack-guard-on-fork=enable --shared-files=network_parent_dirs_pipe:100,v8_context_snapshot_data:101 --field-trial-handle=3,i,1767742148619126290,4177245314570888366,262144 --disable-features=PaintHolding --variations-seed-version --trace-process-track-uuid=3190708989122997041 (dns block)
  • Triggering command: /home/REDACTED/.cache/puppeteer/chrome/linux-145.0.7632.46/chrome-linux64/chrome /home/REDACTED/.cache/puppeteer/chrome/linux-145.0.7632.46/chrome-linux64/chrome --user-data-dir=/tmp/karma-5380339 --enable-automation --no-default-browser-check --no-first-run --disable-default-apps --disable-popup-blocking --disable-translate --disable-REDACTED-timer-throttling --disable-renderer-REDACTEDing --disable-device-discovery-notifications --no-sandbox --disable-gpu --window-size=820,800 --js-flags=--expose-gc http://localhost:9876/?id=5380339 --headless --disable-gpu --disable-dev-shm-usage --remote-debugging-port=9222 (dns block)
  • Triggering command: /proc/self/exe /proc/self/exe --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=network --no-sandbox --disable-dev-shm-usage --use-angle=swiftshader-webgl --crashpad-handler-pid=4859 --enable-crash-reporter=, --noerrdialogs --user-data-dir=/tmp/karma-92561409 --change-stack-guard-on-fork=enable --shared-files=network_parent_dirs_pipe:100,v8_context_snapshot_data:101 --field-trial-handle=3,i,10303362430134108348,5035785990288150114,262144 --disable-features=PaintHolding --variations-seed-version --trace-process-track-uuid=3190708989122997041 (dns block)

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• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

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