Merge bitcoin#30488: depends: Fix CMake-generated libevent*.pc files

8c935e6 depends: Fix CMake-generated `libevent*.pc` files (Hennadii Stepanov)

Pull request description:

  Broken out of bitcoin#30454. This is a backport of the merged upstream PR: libevent/libevent#1622.

  Note that after bitcoin#29835 we might end up dropping pkg-config and using the installed CMake files directly, but that depends on whether or not enough distros actually ship those files.

  Either way, having fixed up .pc files won't hurt.

ACKs for top commit:
  hebasto:
    ACK 8c935e6.
  fanquake:
    ACK 8c935e6

Tree-SHA512: 259c2ad78fb9e90370a7205dc71c40acda1a872f6509435133bc1c4c2c3de57366e80679aa083e13ed85e7966883dc470c0147ee171a2ed0171a18cd5ffc99b3

depends/packages/libevent.mk

@@ -4,6 +4,7 @@ $(package)_download_path=https://github.com/libevent/libevent/releases/download/
 $(package)_file_name=$(package)-$($(package)_version).tar.gz
 $(package)_sha256_hash=92e6de1be9ec176428fd2367677e61ceffc2ee1cb119035037a27d346b0403bb
 $(package)_patches=cmake_fixups.patch
+$(package)_patches+=fix_mingw_link.patch
 $(package)_build_subdir=build
 
 # When building for Windows, we set _WIN32_WINNT to target the same Windows
@@ -17,7 +18,8 @@ define $(package)_set_vars
 endef
 
 define $(package)_preprocess_cmds
-  patch -p1 < $($(package)_patch_dir)/cmake_fixups.patch
+  patch -p1 < $($(package)_patch_dir)/cmake_fixups.patch && \
+  patch -p1 < $($(package)_patch_dir)/fix_mingw_link.patch
 endef
 
 define $(package)_config_cmds

depends/patches/libevent/fix_mingw_link.patch

@@ -0,0 +1,25 @@
+commit d108099913c5fdbe518f3f4d711f248f8522bd10
+Author: Hennadii Stepanov <[email protected]>
+Date:   Mon Apr 22 06:39:35 2024 +0100
+
+    build: Add `Iphlpapi` to `Libs.private` in `*.pc` files on Windows
+
+    It has been required since https://github.com/libevent/libevent/pull/923
+    at least for the `if_nametoindex` call.
+
+    See https://github.com/libevent/libevent/pull/1622.
+
+
+diff --git a/configure.ac b/configure.ac
+index d00e063a..cd1fce37 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -906,7 +906,7 @@ if(WIN32)
+     list(APPEND HDR_PRIVATE WIN32-Code/getopt.h)
+
+     set(EVENT__DNS_USE_FTIME_FOR_ID 1)
+-    set(LIB_PLATFORM ws2_32 shell32 advapi32)
++    set(LIB_PLATFORM ws2_32 shell32 advapi32 iphlpapi)
+     add_definitions(
+             -D_CRT_SECURE_NO_WARNINGS
+             -D_CRT_NONSTDC_NO_DEPRECATE)