Qt: Better wayland detection to enforce xcb

In certain cases, the platform can be "wayland-egl", "wayland-xcomposite", and other values for which I haven't found a full list yet. Instead of matching only "wayland", we now look for "wayland" anywhere in the `QT_QPA_PLATFORM` string in a case-insensitive manner.

Acknowledgements:
`CaseInsensitiveContains`' implementation was heavily inspired by GNU's non-standard glibc `strcasestr` function, which can be found here licensed under GPLv2 or later: https://ftp.gnu.org/gnu/libc/

1 files changed, 16 insertions, 0 deletions

diff --git a/Source/Core/Common/StringUtil.cpp b/Source/Core/Common/StringUtil.cpp
index 935db75d2f..bfd03be9ff 100644
--- a/Source/Core/Common/StringUtil.cpp
+++ b/Source/Core/Common/StringUtil.cpp
@@ -669,6 +669,22 @@ bool CaseInsensitiveEquals(std::string_view a, std::string_view b)
       a, b, [](char ca, char cb) { return Common::ToLower(ca) == Common::ToLower(cb); });
 }
 
+bool CaseInsensitiveContains(std::string_view haystack, std::string_view needle)
+{
+  if (needle.empty())
+    return true;
+
+  for (size_t i = 0; i + needle.size() <= haystack.size(); ++i)
+  {
+    if (std::ranges::equal(needle, haystack.substr(i, needle.size()),
+                           [](char a, char b) { return Common::ToLower(a) == Common::ToLower(b); }))
+    {
+      return true;
+    }
+  }
+  return false;
+}
+
 bool CaseInsensitiveLess::operator()(std::string_view a, std::string_view b) const
 {
   return std::ranges::lexicographical_compare(