deps: float ICU-23262 patch for icu78

[Renegade334]

Fixes: #63041
Refs: https://unicode-org.atlassian.net/browse/ICU-23262

This fixes a bug in ICU 78 whereby absent era data causes libicu to bail out of loading subsequent locale data, including month names. The associated bug is attached to the ICU 79 milestone, so this should be fixed in the next release.

The iso8601 calendar does not contain era names in CLDR 48, but due to an initialization quirk, other fields end up missing in DateTimeFormat output. This is now a much more noticeable issue since certain Temporal objects can only be DateTimeFormat-ed with the iso8601 calendar, and we have had multiple complaints regarding this.

Firefox and Chromium are floating ephemeral patches to the datafile to add the missing era data (https://crrev.com/c/7843156) to bypass this bug. We cannot patch the locale data in our build setup as we use the precompiled ICU data from the sources package, but we can patch out the initialization bug so that the other iso8601 calendar data is intact.

$ JS='new Intl.DateTimeFormat("en-u-ca-iso8601", { dateStyle: "long" }).format()'

$ node -pe "$JS"
2026  22

$ out/Release/node -pe "$JS"
2026 July 22

Patch:

diff -u deps/icu-small/source/i18n/dtfmtsym.cpp tools/icu/patches/78/source/i18n/dtfmtsym.cpp
--- deps/icu-small/source/i18n/dtfmtsym.cpp
+++ tools/icu/patches/78/source/i18n/dtfmtsym.cpp
@@ -2420,7 +2420,7 @@
     initEras(&fEraNames, fEraNamesCount, calendarSink, buildResourcePath(path, gErasTag, gNamesWideTag, status),
             ctebPtr, gNamesWideTag, maxEra, status);
     if (status == U_MISSING_RESOURCE_ERROR) { // Workaround because eras/wide was omitted from CLDR 1.3
-        status = oldStatus;
+        status = U_ZERO_ERROR;
         assignArray(fEraNames, fEraNamesCount, fEras, fErasCount);
     }
     // current ICU4J falls back to abbreviated if narrow eras are missing, so we will too
@@ -2428,7 +2428,7 @@
     initEras(&fNarrowEras, fNarrowErasCount, calendarSink, buildResourcePath(path, gErasTag, gNamesNarrowTag, status),
             ctebPtr, gNamesNarrowTag, maxEra, status);
     if (status == U_MISSING_RESOURCE_ERROR) { // Workaround because eras/wide was omitted from CLDR 1.3
-        status = oldStatus;
+        status = U_ZERO_ERROR;
         assignArray(fNarrowEras, fNarrowErasCount, fEras, fErasCount);
     }

[ovflowd]

Having a temporary patch for this sounds good.

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/75784/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/75801/

[nodejs-github-bot]

Commit Queue failed

- Loading data for nodejs/node/pull/64678
✔  Done loading data for nodejs/node/pull/64678
----------------------------------- PR info ------------------------------------
Title      deps: float ICU-23262 patch for icu78 (#64678)
Author     René <contact.9a5d6388@renegade334.me.uk> (@Renegade334)
Branch     Renegade334:icu78-iso8601-dates -> nodejs:main
Labels     tools, i18n-api, needs-ci, review wanted, commit-queue, icu, lts-watch-v24.x
Commits    1
 - deps: float ICU-23262 patch for icu78
Committers 1
 - Renegade334 <contact.9a5d6388@renegade334.me.uk>
PR-URL: https://github.com/nodejs/node/pull/64678
Fixes: https://github.com/nodejs/node/issues/63041
Refs: https://unicode-org.atlassian.net/browse/ICU-23262
Reviewed-By: Claudio Wunder <cwunder@gnome.org>
Reviewed-By: James M Snell <jasnell@gmail.com>
------------------------------ Generated metadata ------------------------------
PR-URL: https://github.com/nodejs/node/pull/64678
Fixes: https://github.com/nodejs/node/issues/63041
Refs: https://unicode-org.atlassian.net/browse/ICU-23262
Reviewed-By: Claudio Wunder <cwunder@gnome.org>
Reviewed-By: James M Snell <jasnell@gmail.com>
--------------------------------------------------------------------------------
   ℹ  This PR was created on Wed, 22 Jul 2026 16:21:05 GMT
   ✔  Approvals: 2
   ✔  - Claudio Wunder (@ovflowd): https://github.com/nodejs/node/pull/64678#pullrequestreview-4910237836
   ✔  - James M Snell (@jasnell) (TSC): https://github.com/nodejs/node/pull/64678#pullrequestreview-4910813233
   ✘  GitHub CI is still running
   ℹ  Last Full PR CI on 2026-08-12T18:27:40Z: https://ci.nodejs.org/job/node-test-pull-request/75801/
- Querying data for job/node-test-pull-request/75801/
✔  Build data downloaded
   ✔  Last Jenkins CI successful
--------------------------------------------------------------------------------
   ✔  Aborted `git node land` session in /home/runner/work/node/node/.ncu

https://github.com/nodejs/node/actions/runs/31640517938

[Renegade334]

Landed in 167768f