From 87aa4ebd821ebae0023df8658360c724efcf5e00 Mon Sep 17 00:00:00 2001
From: Viktor Szakats <commit@vsz.me>
Date: Tue, 9 Jul 2024 11:39:48 +0200
Subject: [PATCH] cmake: detect `nghttp2` via `pkg-config`, enable by default

- also detect nghttp2 via `pkg-config` to match nghttp3 detection
  and autotools.

- enable nghttp2 by default to match autotools.

Cherry-picked from #14097
Closes #14136
---
 CMake/FindNGHTTP2.cmake | 34 +++++++++++++++++++++++++++-------
 CMakeLists.txt          | 14 +++++++++-----
 2 files changed, 36 insertions(+), 12 deletions(-)

diff --git a/CMake/FindNGHTTP2.cmake b/CMake/FindNGHTTP2.cmake
index 88ac037417..81c11f2147 100644
--- a/CMake/FindNGHTTP2.cmake
+++ b/CMake/FindNGHTTP2.cmake
@@ -21,21 +21,41 @@
 # SPDX-License-Identifier: curl
 #
 ###########################################################################
+
+if(UNIX)
+  find_package(PkgConfig QUIET)
+  pkg_search_module(PC_NGHTTP2 "libnghttp2")
+endif()
+
+find_path(NGHTTP2_INCLUDE_DIR "nghttp2/nghttp2.h"
+  HINTS
+    ${PC_NGHTTP2_INCLUDEDIR}
+    ${PC_NGHTTP2_INCLUDE_DIRS}
+)
+
+find_library(NGHTTP2_LIBRARY NAMES "nghttp2" "nghttp2_static"
+  HINTS
+    ${PC_NGHTTP2_LIBDIR}
+    ${PC_NGHTTP2_LIBRARY_DIRS}
+)
+
+if(PC_NGHTTP2_VERSION)
+  set(NGHTTP2_VERSION ${PC_NGHTTP2_VERSION})
+endif()
+
 include(FindPackageHandleStandardArgs)
-
-find_path(NGHTTP2_INCLUDE_DIR "nghttp2/nghttp2.h")
-
-find_library(NGHTTP2_LIBRARY NAMES nghttp2 nghttp2_static)
-
 find_package_handle_standard_args(NGHTTP2
   FOUND_VAR
     NGHTTP2_FOUND
   REQUIRED_VARS
     NGHTTP2_LIBRARY
     NGHTTP2_INCLUDE_DIR
+  VERSION_VAR NGHTTP2_VERSION
 )
 
-set(NGHTTP2_INCLUDE_DIRS ${NGHTTP2_INCLUDE_DIR})
-set(NGHTTP2_LIBRARIES ${NGHTTP2_LIBRARY})
+if(NGHTTP2_FOUND)
+  set(NGHTTP2_INCLUDE_DIRS ${NGHTTP2_INCLUDE_DIR})
+  set(NGHTTP2_LIBRARIES    ${NGHTTP2_LIBRARY})
+endif()
 
 mark_as_advanced(NGHTTP2_INCLUDE_DIRS NGHTTP2_LIBRARIES)
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 990c745b5f..2b3663e9b0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -701,12 +701,16 @@ if(USE_ECH)
   endif()
 endif()
 
-option(USE_NGHTTP2 "Use nghttp2 library" OFF)
+option(USE_NGHTTP2 "Use nghttp2 library" ON)
 if(USE_NGHTTP2)
-  find_package(NGHTTP2 REQUIRED)
-  include_directories(${NGHTTP2_INCLUDE_DIRS})
-  list(APPEND CURL_LIBS ${NGHTTP2_LIBRARIES})
-  list(APPEND LIBCURL_PC_REQUIRES_PRIVATE "libnghttp2")
+  find_package(NGHTTP2)
+  if(NGHTTP2_FOUND)
+    include_directories(${NGHTTP2_INCLUDE_DIRS})
+    list(APPEND CURL_LIBS ${NGHTTP2_LIBRARIES})
+    list(APPEND LIBCURL_PC_REQUIRES_PRIVATE "libnghttp2")
+  else()
+    set(USE_NGHTTP2 OFF)
+  endif()
 endif()
 
 option(USE_NGTCP2 "Use ngtcp2 and nghttp3 libraries for HTTP/3 support" OFF)