[PATCH 3/5] msvcrt: Make UCRT _beginthread[ex]() hold the DLL reference.

[Arkadiusz Hiler]

MSVCRT's _beginthread[ex]() doesn't exhibit the same behavior and using
ThreadExit() does leak the reference.

FreeLibraryAndExit() has to be used because the DLL may be the only user
of the given CRT.

This fixes Baldur's Gate 3 crashing shortly after launch.

Signed-off-by: Arkadiusz Hiler <ahiler at codeweavers.com>
---
 dlls/msvcrt/msvcrt.h |  1 +
 dlls/msvcrt/thread.c | 39 ++++++++++++++++++++++++++++++++++++---
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/dlls/msvcrt/msvcrt.h b/dlls/msvcrt/msvcrt.h
index 669d8c29a98..ad366a74d86 100644
--- a/dlls/msvcrt/msvcrt.h
+++ b/dlls/msvcrt/msvcrt.h
@@ -168,6 +168,7 @@ struct __thread_data {
     void                           *unk10[100];
 #if _MSVCR_VER >= 140
     _invalid_parameter_handler      invalid_parameter_handler;
+    HMODULE                         module;
 #endif
 };
 
diff --git a/dlls/msvcrt/thread.c b/dlls/msvcrt/thread.c
index d342d57d38c..01500d93d91 100644
--- a/dlls/msvcrt/thread.c
+++ b/dlls/msvcrt/thread.c
@@ -54,6 +54,9 @@ thread_data_t *CDECL msvcrt_get_thread_data(void)
         ptr->random_seed = 1;
         ptr->locinfo = MSVCRT_locale->locinfo;
         ptr->mbcinfo = MSVCRT_locale->mbcinfo;
+#if _MSVCR_VER >= 140
+        ptr->module = NULL;
+#endif
     }
     SetLastError( err );
     return ptr;
@@ -76,8 +79,7 @@ void CDECL _endthread(void)
   } else
       WARN("tls=%p tls->handle=%p\n", tls, tls ? tls->handle : INVALID_HANDLE_VALUE);
 
-  /* FIXME */
-  ExitThread(0);
+  _endthreadex(0);
 }
 
 /*********************************************************************
@@ -88,7 +90,17 @@ void CDECL _endthreadex(
 {
   TRACE("(%d)\n", retval);
 
-  /* FIXME */
+#if _MSVCR_VER >= 140
+  {
+      thread_data_t *tls = TlsGetValue(msvcrt_tls_index);
+
+      if (tls && tls->module != NULL)
+          FreeLibraryAndExitThread(tls->module, retval);
+      else
+          WARN("tls=%p tls->module=%p\n", tls, tls ? tls->module : NULL);
+  }
+#endif
+
   ExitThread(retval);
 }
 
@@ -104,6 +116,15 @@ static DWORD CALLBACK _beginthread_trampoline(LPVOID arg)
     data->handle = local_trampoline.thread;
     free(arg);
 
+#if _MSVCR_VER >= 140
+    if (!GetModuleHandleExW(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
+                (void*)local_trampoline.start_address, &data->module))
+    {
+        data->module = NULL;
+        WARN("failed to get module for the start_address: %d\n", GetLastError());
+    }
+#endif
+
     local_trampoline.start_address(local_trampoline.arglist);
     _endthread();
 }
@@ -163,6 +184,18 @@ static DWORD CALLBACK _beginthreadex_trampoline(LPVOID arg)
     data->handle = local_trampoline.thread;
     free(arg);
 
+#if _MSVCR_VER >= 140
+    {
+        thread_data_t *data = msvcrt_get_thread_data();
+        if (!GetModuleHandleExW(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
+                    (void*)local_trampoline.start_address_ex, &data->module))
+        {
+            data->module = NULL;
+            WARN("failed to get module for the start_address: %d\n", GetLastError());
+        }
+    }
+#endif
+
     retval = local_trampoline.start_address_ex(local_trampoline.arglist);
     _endthreadex(retval);
 }
-- 
2.31.1