From 10d4b34e5c962a0b17836b0bc7483ce3b7c518cc Mon Sep 17 00:00:00 2001
From: Kai Pastor <dg0yt@darc.de>
Date: Fri, 8 May 2026 17:21:52 +0200
Subject: [PATCH] cmake: fix zstd CMake config name

They install `zstdConfig.cmake`,
https://github.com/facebook/zstd/blob/885c79ba4ae8345e006f61bc97b270d4cf7ff076/build/cmake/CMakeModules/ZstdPackage.cmake#L33-L38.
With the `Config.cmake` pattern, this is a case-sensitive package name,
`zstd`.

Follow-up to 8fce3e17e6cb310cd6dbe38ff14869b8fe5827d2 #20814
Closes #21538
---
 CMake/FindZstd.cmake | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/CMake/FindZstd.cmake b/CMake/FindZstd.cmake
index 8dc620a100..176645d97b 100644
--- a/CMake/FindZstd.cmake
+++ b/CMake/FindZstd.cmake
@@ -53,12 +53,12 @@ if(NOT DEFINED ZSTD_INCLUDE_DIR AND
     pkg_check_modules(_zstd ${_zstd_pc_requires})
   endif()
   if(NOT _zstd_FOUND AND CURL_USE_CMAKECONFIG)
-    find_package(Zstd CONFIG QUIET)
+    find_package(zstd CONFIG QUIET)
     # Skip using if older than v1.4.5
-    if(Zstd_CONFIG AND
+    if(zstd_CONFIG AND
        NOT TARGET zstd::libzstd_static AND
        NOT TARGET zstd::libzstd_shared)
-      unset(Zstd_CONFIG)
+      unset(zstd_CONFIG)
     endif()
   endif()
 endif()
@@ -74,9 +74,10 @@ if(_zstd_FOUND)
     set(_zstd_LIBRARIES    "${_zstd_STATIC_LIBRARIES}")
   endif()
   message(STATUS "Found Zstd (via pkg-config): ${_zstd_INCLUDE_DIRS} (found version \"${ZSTD_VERSION}\")")
-elseif(Zstd_CONFIG)
+elseif(zstd_CONFIG)
+  set(Zstd_FOUND TRUE)
   set(ZSTD_FOUND TRUE)
-  set(ZSTD_VERSION ${Zstd_VERSION})
+  set(ZSTD_VERSION ${zstd_VERSION})
   if(ZSTD_USE_STATIC_LIBS)
     set(_zstd_LIBRARIES zstd::libzstd_static)
   elseif(TARGET zstd::libzstd)
@@ -84,7 +85,7 @@ elseif(Zstd_CONFIG)
   else()
     set(_zstd_LIBRARIES zstd::libzstd_shared)
   endif()
-  message(STATUS "Found Zstd (via CMake Config): ${Zstd_CONFIG} (found version \"${ZSTD_VERSION}\")")
+  message(STATUS "Found Zstd (via CMake Config): ${zstd_CONFIG} (found version \"${ZSTD_VERSION}\")")
 else()
   find_path(ZSTD_INCLUDE_DIR NAMES "zstd.h")
   if(ZSTD_USE_STATIC_LIBS)