From 88854b3e4ad02b05c720140159b6d6349924c48b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kacper=20Michaj=C5=82ow?= <kasper93@gmail.com>
Date: Sun, 18 Jan 2026 09:51:26 +0100
Subject: [PATCH 1/3] Revert "ci/build-msys2.sh: disable pdf-build for
 clangarm64"

This reverts commit 25aa402f1de1335c6bca4b81455485164ff4598a.
---
 ci/build-msys2.sh | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/ci/build-msys2.sh b/ci/build-msys2.sh
index 80bad4cbee1d6..cab93e7005cbd 100755
--- a/ci/build-msys2.sh
+++ b/ci/build-msys2.sh
@@ -19,10 +19,6 @@ build_subrandr "/$SYS"
 echo "::endgroup::"
 args+=(-Dsubrandr=enabled)
 
-[[ "$SYS" == "clangarm64" ]] && args+=(
-  -Dpdf-build=disabled
-)
-
 meson setup build $common_args "${args[@]}"
 meson compile -C build
 ./build/mpv.com -v --no-config

From 636cf7d2b0a42374a43f12d0d9ac0e73e440eadc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kacper=20Michaj=C5=82ow?= <kasper93@gmail.com>
Date: Sun, 18 Jan 2026 10:03:19 +0100
Subject: [PATCH 2/3] ci/msys2: build also clang64 without ASAN

To cross compare results on basic build.
---
 .github/workflows/build.yml | 4 ++++
 ci/build-msys2.sh           | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index e657ad930ef05..3a60471d80b41 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -572,6 +572,9 @@ jobs:
         include:
           - sys: "clang64"
             os: "windows-latest"
+          - sys: "clang64"
+            os: "windows-latest"
+            asan: true
           - sys: "mingw64"
             os: "windows-latest"
           - sys: "ucrt64"
@@ -627,6 +630,7 @@ jobs:
           ./ci/build-msys2.sh meson
         env:
           SYS: ${{ matrix.sys }}
+          ASAN: ${{ matrix.asan }}
 
       - name: Print meson log
         if: ${{ failure() && steps.build.outcome == 'failure' }}
diff --git a/ci/build-msys2.sh b/ci/build-msys2.sh
index cab93e7005cbd..d108bd6a2558f 100755
--- a/ci/build-msys2.sh
+++ b/ci/build-msys2.sh
@@ -8,7 +8,7 @@ args=(
   -D{egl-angle-lib,egl-angle-win32,pdf-build,rubberband,win32-smtc}=enabled
 )
 
-if [[ "$SYS" == "clang64" ]]; then
+if [[ -n "$ASAN" ]]; then
     args+=(
       -Db_sanitize=address,undefined
     )

From 5af4fcc5d744ca00aed9e9fc2fca925bdccd9434 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kacper=20Michaj=C5=82ow?= <kasper93@gmail.com>
Date: Sun, 18 Jan 2026 10:04:20 +0100
Subject: [PATCH 3/3] ci/msys2: add build with -ftrivial-auto-var-init

Just to catch uninitialized variables early. Build all three                                                                                          unint/zero/pattern to compare the results between them and we don't                                                                                   accidentally depend on implicit initialization in tests.
---
 .github/workflows/build.yml | 8 ++++++++
 ci/build-msys2.sh           | 7 +++++++
 2 files changed, 15 insertions(+)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 3a60471d80b41..5e59b65edde16 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -572,9 +572,16 @@ jobs:
         include:
           - sys: "clang64"
             os: "windows-latest"
+            auto-var-init: "uninitialized"
           - sys: "clang64"
             os: "windows-latest"
             asan: true
+          - sys: "clang64"
+            os: "windows-latest"
+            auto-var-init: "zero"
+          - sys: "clang64"
+            os: "windows-latest"
+            auto-var-init: "pattern"
           - sys: "mingw64"
             os: "windows-latest"
           - sys: "ucrt64"
@@ -631,6 +638,7 @@ jobs:
         env:
           SYS: ${{ matrix.sys }}
           ASAN: ${{ matrix.asan }}
+          AUTO_VAR_INIT: ${{ matrix.auto-var-init }}
 
       - name: Print meson log
         if: ${{ failure() && steps.build.outcome == 'failure' }}
diff --git a/ci/build-msys2.sh b/ci/build-msys2.sh
index d108bd6a2558f..9e2f88a377bed 100755
--- a/ci/build-msys2.sh
+++ b/ci/build-msys2.sh
@@ -14,6 +14,13 @@ if [[ -n "$ASAN" ]]; then
     )
 fi
 
+if [[ -n "$AUTO_VAR_INIT" ]]; then
+    args+=(
+        -Dc_args="-ftrivial-auto-var-init=$AUTO_VAR_INIT"
+        -Dcpp_args="-ftrivial-auto-var-init=$AUTO_VAR_INIT"
+    )
+fi
+
 echo "::group::Building subrandr"
 build_subrandr "/$SYS"
 echo "::endgroup::"