Maintenance: fix bug, add headless-git.exe

Makefile

@@ -2522,6 +2522,13 @@ compat/nedmalloc/nedmalloc.sp compat/nedmalloc/nedmalloc.o: EXTRA_CPPFLAGS = \
 compat/nedmalloc/nedmalloc.sp: SP_EXTRA_FLAGS += -Wno-non-pointer-null
 endif
 
+headless-git.o: compat/win32/headless.c
+	$(QUIET_CC)$(CC) $(ALL_CFLAGS) $(COMPAT_CFLAGS) \
+		-fno-stack-protector -o $@ -c -Wall -Wwrite-strings $<
+
+headless-git$X: headless-git.o git.res
+	$(QUIET_LINK)$(CC) $(ALL_LDFLAGS) -mwindows $(COMPAT_CFLAGS) -o $@ $^
+
 git-%$X: %.o GIT-LDFLAGS $(GITLIBS)
 	$(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) $(LIBS)
 

builtin/gc.c

@@ -1610,7 +1610,7 @@ static int launchctl_schedule_plist(const char *exec_path, enum schedule_priorit
 		die(_("failed to create directories for '%s'"), filename);
 	plist = xfopen(filename, "w");
 
-	preamble = "<?xml version=\"1.0\" encoding=\"US-ASCII\"?>\n"
+	preamble = "<?xml version=\"1.0\"?>\n"
 		   "<!DOCTYPE plist PUBLIC \"-//Apple//DTD PLIST 1.0//EN\" \"http://www.apple.com/DTDs/PropertyList-1.0.dtd\">\n"
 		   "<plist version=\"1.0\">"
 		   "<dict>\n"
@@ -1813,7 +1813,7 @@ static int schtasks_schedule_task(const char *exec_path, enum schedule_priority
 	      "</Settings>\n"
 	      "<Actions Context=\"Author\">\n"
 	      "<Exec>\n"
-	      "<Command>\"%s\\git.exe\"</Command>\n"
+	      "<Command>\"%s\\headless-git.exe\"</Command>\n"
 	      "<Arguments>--exec-path=\"%s\" for-each-repo --config=maintenance.repo maintenance run --schedule=%s</Arguments>\n"
 	      "</Exec>\n"
 	      "</Actions>\n"

compat/win32/headless.c

@@ -0,0 +1,114 @@
+/*
+ * headless Git - run Git without opening a console window on Windows
+ */
+
+#define STRICT
+#define WIN32_LEAN_AND_MEAN
+#define UNICODE
+#define _UNICODE
+#include <windows.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <wchar.h>
+
+/*
+ * If `dir` contains the path to a Git exec directory, extend `PATH` to
+ * include the corresponding `bin/` directory (which is where all those
+ * `.dll` files needed by `git.exe` are, on Windows).
+ */
+static int extend_path(wchar_t *dir, size_t dir_len)
+{
+	const wchar_t *suffix = L"\\libexec\\git-core";
+	size_t suffix_len = wcslen(suffix);
+	wchar_t *env;
+	DWORD len;
+
+	if (dir_len < suffix_len)
+		return 0;
+
+	dir_len -= suffix_len;
+	if (memcmp(dir + dir_len, suffix, suffix_len * sizeof(wchar_t)))
+		return 0;
+
+	len = GetEnvironmentVariableW(L"PATH", NULL, 0);
+	if (!len)
+		return 0;
+
+	env = _alloca((dir_len + 5 + len) * sizeof(wchar_t));
+	wcsncpy(env, dir, dir_len);
+	wcscpy(env + dir_len, L"\\bin;");
+	if (!GetEnvironmentVariableW(L"PATH", env + dir_len + 5, len))
+		return 0;
+
+	SetEnvironmentVariableW(L"PATH", env);
+	return 1;
+}
+
+int WINAPI wWinMain(HINSTANCE instance, HINSTANCE previous_instance,
+		    wchar_t *command_line, int show)
+{
+	wchar_t git_command_line[32768];
+	size_t size = sizeof(git_command_line) / sizeof(wchar_t);
+	const wchar_t *needs_quotes = L"";
+	int slash = 0, i;
+
+	STARTUPINFO startup_info = {
+		.dwFlags = STARTF_USESHOWWINDOW,
+		.wShowWindow = SW_HIDE,
+	};
+	PROCESS_INFORMATION process_info = { 0 };
+	DWORD creation_flags = CREATE_UNICODE_ENVIRONMENT |
+		CREATE_NEW_CONSOLE | CREATE_NO_WINDOW;
+	DWORD exit_code;
+
+	/* First, determine the full path of argv[0] */
+	for (i = 0; _wpgmptr[i]; i++)
+		if (_wpgmptr[i] == L' ')
+			needs_quotes = L"\"";
+		else if (_wpgmptr[i] == L'\\')
+			slash = i;
+
+	if (slash + 11 >= sizeof(git_command_line) / sizeof(wchar_t))
+		return 127; /* Too long path */
+
+	/* If it is in Git's exec path, add the bin/ directory to the PATH */
+	extend_path(_wpgmptr, slash);
+
+	/* Then, add the full path of `git.exe` as argv[0] */
+	i = swprintf_s(git_command_line, size, L"%ls%.*ls\\git.exe%ls",
+		       needs_quotes, slash, _wpgmptr, needs_quotes);
+	if (i < 0)
+		return 127; /* Too long path */
+
+	if (*command_line) {
+		/* Now, append the command-line arguments */
+		i = swprintf_s(git_command_line + i, size - i,
+			       L" %ls", command_line);
+		if (i < 0)
+			return 127;
+	}
+
+	startup_info.cb = sizeof(STARTUPINFO);
+
+	startup_info.hStdInput = GetStdHandle(STD_INPUT_HANDLE);
+	startup_info.hStdOutput = GetStdHandle(STD_OUTPUT_HANDLE);
+	startup_info.hStdError = GetStdHandle(STD_ERROR_HANDLE);
+
+	if (!CreateProcess(NULL, /* infer argv[0] from the command line */
+			   git_command_line, /* modified command line */
+			   NULL, /* inherit process handles? */
+			   NULL, /* inherit thread handles? */
+			   FALSE, /* handles inheritable? */
+			   creation_flags,
+			   NULL, /* use this process' environment */
+			   NULL, /* use this process' working directory */
+			   &startup_info, &process_info))
+		return 129; /* could not start */
+	WaitForSingleObject(process_info.hProcess, INFINITE);
+	if (!GetExitCodeProcess(process_info.hProcess, &exit_code)) {
+		CloseHandle(process_info.hProcess);
+		return 130; /* Could not determine exit code? */
+	}
+
+	return (int)exit_code;
+}

config.mak.uname

@@ -486,6 +486,8 @@ else
 endif
 	X = .exe
 
+	EXTRA_PROGRAMS += headless-git$X
+
 compat/msvc.o: compat/msvc.c compat/mingw.c GIT-CFLAGS
 endif
 ifeq ($(uname_S),Interix)
@@ -627,6 +629,7 @@ ifneq (,$(findstring MINGW,$(uname_S)))
 	RC = windres -O coff
 	NATIVE_CRLF = YesPlease
 	X = .exe
+	EXTRA_PROGRAMS += headless-git$X
 ifneq (,$(wildcard ../THIS_IS_MSYSGIT))
 	htmldir = doc/git/html/
 	prefix =

contrib/buildsystems/CMakeLists.txt

@@ -642,6 +642,9 @@ if(WIN32)
 	else()
 		message(FATAL_ERROR "Unhandled compiler: ${CMAKE_C_COMPILER_ID}")
 	endif()
+
+	add_executable(headless-git ${CMAKE_SOURCE_DIR}/compat/win32/headless.c)
+	target_link_options(headless-git PUBLIC /NOLOGO /ENTRY:wWinMainCRTStartup /SUBSYSTEM:WINDOWS)
 elseif(UNIX)
 	target_link_libraries(common-main pthread rt)
 endif()