win32: teach the allocator to deal with crtdbg

Move the MSVC C runtime debugging bits into the allocator's global init
function.

src/alloc.c

@@ -10,6 +10,11 @@
 #include "allocators/stdalloc.h"
 #include "allocators/win32_crtdbg.h"
 
+#if defined(GIT_MSVC_CRTDBG)
+# include "win32/w32_stack.h"
+# include "win32/w32_crtdbg_stacktrace.h"
+#endif
+
 git_allocator git__allocator;
 
 static int setup_default_allocator(void)
@@ -21,8 +26,23 @@ static int setup_default_allocator(void)
 #endif
 }
 
+#if defined(GIT_MSVC_CRTDBG)
+static void allocator_global_shutdown(void)
+{
+	git_win32__crtdbg_stacktrace_cleanup();
+	git_win32__stack_cleanup();
+}
+#endif
+
 int git_allocator_global_init(void)
 {
+#if defined(GIT_MSVC_CRTDBG)
+	git_win32__crtdbg_stacktrace_init();
+	git_win32__stack_init();
+
+	git__on_shutdown(allocator_global_shutdown);
+#endif
+
 	/*
 	 * We don't want to overwrite any allocator which has been set before
 	 * the init function is called.

src/allocators/win32_crtdbg.c

@@ -9,6 +9,7 @@
 
 #if defined(GIT_MSVC_CRTDBG)
 
+#include "win32/w32_stack.h"
 #include "win32/w32_crtdbg_stacktrace.h"
 
 static void *crtdbg__malloc(size_t len, const char *file, int line)

src/global.c

@@ -19,11 +19,7 @@
 #include "thread-utils.h"
 #include "git2/global.h"
 #include "transports/ssh.h"
-
-#if defined(GIT_MSVC_CRTDBG)
 #include "win32/w32_stack.h"
-#include "win32/w32_crtdbg_stacktrace.h"
-#endif
 
 git_mutex git__mwindow_mutex;
 
@@ -72,12 +68,6 @@ static int init_common(void)
 	size_t i;
 	int ret;
 
-	/* Initialize the CRT debug allocator first, before our first malloc */
-#if defined(GIT_MSVC_CRTDBG)
-	git_win32__crtdbg_stacktrace_init();
-	git_win32__stack_init();
-#endif
-
 	/* Initialize subsystems that have global state */
 	for (i = 0; i < ARRAY_SIZE(git__init_callbacks); i++)
 		if ((ret = git__init_callbacks[i]()) != 0)
@@ -200,11 +190,6 @@ int git_libgit2_shutdown(void)
 
 		FlsFree(_fls_index);
 		git_mutex_free(&git__mwindow_mutex);
-
-#if defined(GIT_MSVC_CRTDBG)
-		git_win32__crtdbg_stacktrace_cleanup();
-		git_win32__stack_cleanup();
-#endif
 	}
 
 	/* Exit the lock */