From 4a2281923ab608b5aa120499d8c13bd39c245d46 Mon Sep 17 00:00:00 2001
From: Efraim Flashner <efraim@flashner.co.il>
Date: Mon, 6 Oct 2025 10:17:11 +0300
Subject: [PATCH] gnu: qtbase: Always find libvulkan.

Fixes: guix/guix#3330

* gnu/packages/qt.scm (qtbase)[source]: Add patch.
[arguments]: Adjust a phase to substitute the location for libvulkan.so.
* gnu/packages/patches/qtbase-patch-libvulkan.patch: New file.
* gnu/local.mk (dist_patch_DATA): Register it.

Co-authored-by: kestrelwx <kestrel.w@proton.me>
Change-Id: I39f1be5a30c5c17a4e4ea6c853b475f20ba8272c
Signed-off-by: Andreas Enge <andreas@enge.fr>
---
 gnu/local.mk                                  |  1 +
 .../patches/qtbase-patch-libvulkan.patch      | 28 +++++++++++++++++++
 gnu/packages/qt.scm                           |  9 +++++-
 3 files changed, 37 insertions(+), 1 deletion(-)
 create mode 100644 gnu/packages/patches/qtbase-patch-libvulkan.patch

diff --git a/gnu/local.mk b/gnu/local.mk
index 816459723cd9585252c4a106a222bfdb887200a3..2e2f46783c636e67a7600252014b8e5b61348bf9 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -2212,6 +2212,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/qtbase-qmake-fix-includedir.patch 	\
   %D%/packages/patches/qtbase-qmlimportscanner-qml-import-path.patch 	\
   %D%/packages/patches/qtbase-moc-ignore-gcc-macro.patch	\
+  %D%/packages/patches/qtbase-patch-libvulkan.patch		\
   %D%/packages/patches/qtbase-qmake-use-libname.patch		\
   %D%/packages/patches/qtbase-5-use-TZDIR.patch			\
   %D%/packages/patches/qtscript-disable-tests.patch		\
diff --git a/gnu/packages/patches/qtbase-patch-libvulkan.patch b/gnu/packages/patches/qtbase-patch-libvulkan.patch
new file mode 100644
index 0000000000000000000000000000000000000000..b8b3847504ec1431331f6b87b5413d94a0d50fd3
--- /dev/null
+++ b/gnu/packages/patches/qtbase-patch-libvulkan.patch
@@ -0,0 +1,28 @@
+Add the full name for libvulkan.so.1 so that we can patch it in the 'build phase.
+Not sent upstream.
+
+diff --git a/src/gui/vulkan/qbasicvulkanplatforminstance.cpp b/src/gui/vulkan/qbasicvulkanplatforminstance.cpp
+index 47d9a7e9..80c929e5 100644
+--- a/src/gui/vulkan/qbasicvulkanplatforminstance.cpp
++++ b/src/gui/vulkan/qbasicvulkanplatforminstance.cpp
+@@ -45,7 +45,7 @@ QBasicPlatformVulkanInstance::~QBasicPlatformVulkanInstance()
+ 
+ void QBasicPlatformVulkanInstance::loadVulkanLibrary(const QString &defaultLibraryName, int defaultLibraryVersion)
+ {
+-    QVarLengthArray<std::pair<QString, int>, 3> loadList;
++    QVarLengthArray<std::pair<QString, int>, 4> loadList;
+ 
+     // First in the list of libraries to try is the manual override, relevant on
+     // embedded systems without a Vulkan loader and possibly with custom vendor
+@@ -63,6 +63,11 @@ void QBasicPlatformVulkanInstance::loadVulkanLibrary(const QString &defaultLibra
+     if (defaultLibraryVersion >= 0)
+         loadList.append({ defaultLibraryName, -1 });
+ 
++#ifdef __linux__
++    // As a fallback we append to the list the full default name of libvulkan.
++    loadList.append({ QString::fromUtf8("libvulkan.so.1"), -1 });
++#endif
++
+     bool ok = false;
+     for (const auto &lib : loadList) {
+         m_vulkanLib.reset(new QLibrary);
diff --git a/gnu/packages/qt.scm b/gnu/packages/qt.scm
index f6bfd73ce3724dc3bceba81c9166c05fb5d271a9..917b72c6c004583b9920ee32aeb357587a7ae116 100644
--- a/gnu/packages/qt.scm
+++ b/gnu/packages/qt.scm
@@ -786,7 +786,8 @@ developers using C++ or QML, a CSS & JavaScript like language.")
                 "qtbase-absolute-runpath.patch"
                 "qtbase-qmake-use-libname.patch"
                 "qtbase-qmlimportscanner-qml-import-path.patch"
-                "qtbase-qmake-fix-includedir.patch"))))
+                "qtbase-qmake-fix-includedir.patch"
+                "qtbase-patch-libvulkan.patch"))))
     (build-system cmake-build-system)
     (arguments
      (substitute-keyword-arguments (package-arguments qtbase-5)
@@ -897,6 +898,11 @@ tst_qt_cmake_create.cpp"
                   (("/bin/ls")
                    (search-input-file inputs "bin/ls")))
 
+                ;; Patch the added reference for libvulkan.so
+                (substitute* "src/gui/vulkan/qbasicvulkanplatforminstance.cpp"
+                  (("libvulkan\\.so\\.1")
+                   (search-input-file inputs "lib/libvulkan.so.1")))
+
                 ;; Use shared-mime-info as the default MIME type database.
                 (substitute* "src/corelib/mimetypes/qmimedatabase.cpp"
                   (("return dirs;" all)
@@ -1213,6 +1219,7 @@ tst_qt_cmake_create.cpp"
                 libxcb
                 libxext
                 shared-mime-info
+                vulkan-loader
                 xcb-util-cursor
                 `(,zstd "lib"))))
     (native-search-paths