From c5ab604e9d3f10a28e3d369d0ba4911bbde59276 Mon Sep 17 00:00:00 2001
From: Ivan K <krylov.r00t@gmail.com>
Date: Mon, 1 Jun 2026 15:02:14 +0300
Subject: [PATCH 1/3] GHA: add locale-specific checks

---
 .github/workflows/R-CMD-check.yaml | 51 ++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/.github/workflows/R-CMD-check.yaml b/.github/workflows/R-CMD-check.yaml
index cc54295fc7..56dc522633 100644
--- a/.github/workflows/R-CMD-check.yaml
+++ b/.github/workflows/R-CMD-check.yaml
@@ -71,3 +71,54 @@ jobs:
       - uses: yihui/actions/check-r-package@HEAD
         with:
           check-args: "--no-manual --as-cran"
+
+  R-CMD-check-locale:
+    runs-on: ${{ matrix.os }}
+
+    name: ${{ matrix.os }}, R-${{ matrix.r }}, LC_CTYPE=${{ matrix.locale }}
+
+    strategy:
+      fail-fast: true
+      matrix:
+        os: [ubuntu-22.04]
+        r: ['release']
+        locale: ['fr_CA.ISO-8859-1', 'zh_CN.GB18030', 'ru_RU.KOI8-R']
+
+    env:
+      GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
+      _R_CHECK_RD_CHECKRD_MINLEVEL_: -Inf
+      _R_CHECK_RD_CONTENTS_VALUE_: 1
+
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: r-lib/actions/setup-r@v2
+        with:
+          r-version: ${{ matrix.r }}
+
+      - name: Configure locale
+        run: |
+          echo ${{ matrix.locale }} `echo ${{ matrix.locale }} | sed 's/.*\.//'` | sudo tee -a /etc/locale.gen
+          sudo locale-gen --keep-existing
+
+      - uses: yihui/actions/setup-r-dependencies@HEAD
+
+      - name: Override R for locale-specific check
+        run: |
+          sudo mkdir -p /override
+          # poor man's luit that doesn't require a tty
+          sudo tee /override/R <<EOF # no quotes => expand backticks, dollars
+          #!/bin/bash
+          set -o pipefail
+          exec stdbuf -o L -e L `which R` "\$@" 2>&1 | while read line; do
+            echo "\$line" | iconv -t UTF-8
+          done
+          EOF
+          sudo chmod +x /override/R
+          echo PATH=/override:$PATH >> $GITHUB_ENV
+
+      - uses: yihui/actions/check-r-package@HEAD
+        with:
+          check-args: "--no-manual"
+        env:
+          LC_CTYPE: ${{ matrix.locale }}

From 52271bbb0cc12d3474a3d8d0d7dd82dea08842e1 Mon Sep 17 00:00:00 2001
From: Ivan K <krylov.r00t@gmail.com>
Date: Sat, 6 Jun 2026 23:32:46 +0300
Subject: [PATCH 2/3] Fix tests 2298.*

In a non-UTF-8 locale capable of representing a-umlaut, o-umlaut,
u-umlaut, encode from the locale encoding, not UTF-8.
---
 inst/tests/tests.Rraw | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/inst/tests/tests.Rraw b/inst/tests/tests.Rraw
index 687bf929ed..1de5c8e06e 100644
--- a/inst/tests/tests.Rraw
+++ b/inst/tests/tests.Rraw
@@ -20283,7 +20283,7 @@ local(if (utf8_check(c("\u00e4", "\u00f6", "\u00fc"))) {
   # a-umlaut, o-umlaut, u-umlaut
   eval(parse(text = '  # eval(parse()) defers parsing to runtime; see utf8_check description
     setnames(x , c("\u00e4", "\u00f6", "\u00fc"))
-    setnames(y , iconv(c("\u00f6", "\u00fc", "\u00e4"), from = "UTF-8", to = "latin1"))
+    setnames(y , iconv(c("\u00f6", "\u00fc", "\u00e4"), from = "", to = "latin1"))
     test(2298.1, rbindlist(list(x,y), use.names=TRUE), data.table("\u00e4"=c(1,6), "\u00f6"=c(2,4), "\u00fc"=c(3,5)))
     test(2298.2, rbindlist(list(y,x), use.names=TRUE), data.table("\u00f6"=c(4,2), "\u00fc"=c(5,3), "\u00e4"=c(6,1)))
     set(y, j="\u00e4", value=NULL)

From 29ad3b031433183de6d4eaa61060a76603f689e0 Mon Sep 17 00:00:00 2001
From: Ivan K <krylov.r00t@gmail.com>
Date: Sat, 18 Jul 2026 20:12:22 +0300
Subject: [PATCH 3/3] Drop unnecessary environment variables

---
 .github/workflows/R-CMD-check.yaml | 2 --
 1 file changed, 2 deletions(-)

diff --git a/.github/workflows/R-CMD-check.yaml b/.github/workflows/R-CMD-check.yaml
index 56dc522633..1e437a2e2a 100644
--- a/.github/workflows/R-CMD-check.yaml
+++ b/.github/workflows/R-CMD-check.yaml
@@ -86,8 +86,6 @@ jobs:
 
     env:
       GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
-      _R_CHECK_RD_CHECKRD_MINLEVEL_: -Inf
-      _R_CHECK_RD_CONTENTS_VALUE_: 1
 
     steps:
       - uses: actions/checkout@v6