23 files changed, 296 insertions, 57 deletions

diff --git a/compat/compiler.h b/compat/compiler.h
index e9ad9db84f..e12e426404 100644
--- a/compat/compiler.h
+++ b/compat/compiler.h
@@ -9,7 +9,7 @@
 
 static inline void get_compiler_info(struct strbuf *info)
 {
-	int len = info->len;
+	size_t len = info->len;
 #ifdef __clang__
 	strbuf_addf(info, "clang: %s\n", __clang_version__);
 #elif defined(__GNUC__)
@@ -27,7 +27,7 @@ static inline void get_compiler_info(struct strbuf *info)
 
 static inline void get_libc_info(struct strbuf *info)
 {
-	int len = info->len;
+	size_t len = info->len;
 
 #ifdef __GLIBC__
 	strbuf_addf(info, "glibc: %s\n", gnu_get_libc_version());
diff --git a/compat/fsmonitor/fsm-ipc-darwin.c b/compat/fsmonitor/fsm-ipc-darwin.c
index 52f4f29720..fe149a1b37 100644
--- a/compat/fsmonitor/fsm-ipc-darwin.c
+++ b/compat/fsmonitor/fsm-ipc-darwin.c
@@ -1,3 +1,5 @@
+#define USE_THE_REPOSITORY_VARIABLE
+
 #include "git-compat-util.h"
 #include "config.h"
 #include "gettext.h"
diff --git a/compat/fsmonitor/fsm-listen-darwin.c b/compat/fsmonitor/fsm-listen-darwin.c
index 2fc67442eb..dfa551459d 100644
--- a/compat/fsmonitor/fsm-listen-darwin.c
+++ b/compat/fsmonitor/fsm-listen-darwin.c
@@ -516,6 +516,12 @@ void fsm_listen__loop(struct fsmonitor_daemon_state *state)
 	}
 	data->stream_started = 1;
 
+	/*
+	 * Our fs event listener is now running, so it's safe to start
+	 * serving client requests.
+	 */
+	ipc_server_start_async(state->ipc_server_data);
+
 	pthread_mutex_lock(&data->dq_lock);
 	pthread_cond_wait(&data->dq_finished, &data->dq_lock);
 	pthread_mutex_unlock(&data->dq_lock);
diff --git a/compat/fsmonitor/fsm-listen-win32.c b/compat/fsmonitor/fsm-listen-win32.c
index 5a21dade7b..9a6efc9bea 100644
--- a/compat/fsmonitor/fsm-listen-win32.c
+++ b/compat/fsmonitor/fsm-listen-win32.c
@@ -431,9 +431,9 @@ static int recv_rdcw_watch(struct one_watch *watch)
 	 * but I observed ERROR_ACCESS_DENIED (0x05) errors during
 	 * testing.
 	 *
-	 * Note that we only get notificaiton events for events
+	 * Note that we only get notification events for events
 	 * *within* the directory, not *on* the directory itself.
-	 * (These might be properies of the parent directory, for
+	 * (These might be properties of the parent directory, for
 	 * example).
 	 *
 	 * NEEDSWORK: We might try to check for the deleted directory
@@ -741,6 +741,12 @@ void fsm_listen__loop(struct fsmonitor_daemon_state *state)
 	    start_rdcw_watch(data->watch_gitdir) == -1)
 		goto force_error_stop;
 
+	/*
+	 * Now that we've established the rdcw watches, we can start
+	 * serving clients.
+	 */
+	ipc_server_start_async(state->ipc_server_data);
+
 	for (;;) {
 		dwWait = WaitForMultipleObjects(data->nr_listener_handles,
 						data->hListener,
diff --git a/compat/mingw.c b/compat/mingw.c
index 29d3f09768..63f36c893b 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -1,3 +1,5 @@
+#define USE_THE_REPOSITORY_VARIABLE
+
 #include "../git-compat-util.h"
 #include "win32.h"
 #include <aclapi.h>
@@ -243,7 +245,8 @@ static enum hide_dotfiles_type hide_dotfiles = HIDE_DOTFILES_DOTGITONLY;
 static char *unset_environment_variables;
 
 int mingw_core_config(const char *var, const char *value,
-		      const struct config_context *ctx, void *cb)
+		      const struct config_context *ctx UNUSED,
+		      void *cb UNUSED)
 {
 	if (!strcmp(var, "core.hidedotfiles")) {
 		if (value && !strcasecmp(value, "dotgitonly"))
@@ -453,7 +456,7 @@ static int set_hidden_flag(const wchar_t *path, int set)
 	return -1;
 }
 
-int mingw_mkdir(const char *path, int mode)
+int mingw_mkdir(const char *path, int mode UNUSED)
 {
 	int ret;
 	wchar_t wpath[MAX_PATH];
@@ -499,7 +502,7 @@ static int mingw_open_append(wchar_t const *wfilename, int oflags, ...)
 	 * to append to the file.
 	 */
 	handle = CreateFileW(wfilename, FILE_APPEND_DATA,
-			FILE_SHARE_WRITE | FILE_SHARE_READ,
+			FILE_SHARE_WRITE | FILE_SHARE_READ | FILE_SHARE_DELETE,
 			NULL, create, FILE_ATTRIBUTE_NORMAL, NULL);
 	if (handle == INVALID_HANDLE_VALUE) {
 		DWORD err = GetLastError();
@@ -530,6 +533,70 @@ static int mingw_open_append(wchar_t const *wfilename, int oflags, ...)
 }
 
 /*
+ * Ideally, we'd use `_wopen()` to implement this functionality so that we
+ * don't have to reimplement it, but unfortunately we do not have tight control
+ * over the share mode there. And while `_wsopen()` and friends exist that give
+ * us _some_ control over the share mode, this family of functions doesn't give
+ * us the ability to enable FILE_SHARE_DELETE, either. But this is a strict
+ * requirement for us though so that we can unlink or rename over files that
+ * are held open by another process.
+ *
+ * We are thus forced to implement our own emulation of `open()`. To make our
+ * life simpler we only implement basic support for this, namely opening
+ * existing files for reading and/or writing. This means that newly created
+ * files won't have their sharing mode set up correctly, but for now I couldn't
+ * find any case where this matters. We may have to revisit that in the future
+ * though based on our needs.
+ */
+static int mingw_open_existing(const wchar_t *filename, int oflags, ...)
+{
+	SECURITY_ATTRIBUTES security_attributes = {
+		.nLength = sizeof(security_attributes),
+		.bInheritHandle = !(oflags & O_NOINHERIT),
+	};
+	HANDLE handle;
+	DWORD access;
+	int fd;
+
+	/* We only support basic flags. */
+	if (oflags & ~(O_ACCMODE | O_NOINHERIT)) {
+		errno = ENOSYS;
+		return -1;
+	}
+
+	switch (oflags & O_ACCMODE) {
+	case O_RDWR:
+		access = GENERIC_READ | GENERIC_WRITE;
+		break;
+	case O_WRONLY:
+		access = GENERIC_WRITE;
+		break;
+	default:
+		access = GENERIC_READ;
+		break;
+	}
+
+	handle = CreateFileW(filename, access,
+			     FILE_SHARE_WRITE | FILE_SHARE_READ | FILE_SHARE_DELETE,
+			     &security_attributes, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
+	if (handle == INVALID_HANDLE_VALUE) {
+		DWORD err = GetLastError();
+
+		/* See `mingw_open_append()` for why we have this conversion. */
+		if (err == ERROR_INVALID_PARAMETER)
+			err = ERROR_PATH_NOT_FOUND;
+
+		errno = err_win_to_posix(err);
+		return -1;
+	}
+
+	fd = _open_osfhandle((intptr_t)handle, oflags | O_BINARY);
+	if (fd < 0)
+		CloseHandle(handle);
+	return fd;
+}
+
+/*
  * Does the pathname map to the local named pipe filesystem?
  * That is, does it have a "//./pipe/" prefix?
  */
@@ -564,6 +631,8 @@ int mingw_open (const char *filename, int oflags, ...)
 
 	if ((oflags & O_APPEND) && !is_local_named_pipe_path(filename))
 		open_fn = mingw_open_append;
+	else if (!(oflags & ~(O_ACCMODE | O_NOINHERIT)))
+		open_fn = mingw_open_existing;
 	else
 		open_fn = _wopen;
 
@@ -597,7 +666,7 @@ int mingw_open (const char *filename, int oflags, ...)
 	return fd;
 }
 
-static BOOL WINAPI ctrl_ignore(DWORD type)
+static BOOL WINAPI ctrl_ignore(DWORD type UNUSED)
 {
 	return TRUE;
 }
@@ -779,7 +848,7 @@ static inline void filetime_to_timespec(const FILETIME *ft, struct timespec *ts)
  */
 static int has_valid_directory_prefix(wchar_t *wfilename)
 {
-	int n = wcslen(wfilename);
+	size_t n = wcslen(wfilename);
 
 	while (n > 0) {
 		wchar_t c = wfilename[--n];
@@ -888,7 +957,7 @@ static int do_lstat(int follow, const char *file_name, struct stat *buf)
  */
 static int do_stat_internal(int follow, const char *file_name, struct stat *buf)
 {
-	int namelen;
+	size_t namelen;
 	char alt_name[PATH_MAX];
 
 	if (!do_lstat(follow, file_name, buf))
@@ -1003,7 +1072,7 @@ int mingw_utime (const char *file_name, const struct utimbuf *times)
 
 	osfilehandle = CreateFileW(wfilename,
 				   FILE_WRITE_ATTRIBUTES,
-				   0 /*FileShare.None*/,
+				   FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
 				   NULL,
 				   OPEN_EXISTING,
 				   (attrs != INVALID_FILE_ATTRIBUTES &&
@@ -1085,7 +1154,7 @@ int mkstemp(char *template)
 	return git_mkstemp_mode(template, 0600);
 }
 
-int gettimeofday(struct timeval *tv, void *tz)
+int gettimeofday(struct timeval *tv, void *tz UNUSED)
 {
 	FILETIME ft;
 	long long hnsec;
@@ -1271,7 +1340,8 @@ static const char *parse_interpreter(const char *cmd)
 {
 	static char buf[100];
 	char *p, *opt;
-	int n, fd;
+	ssize_t n; /* read() can return negative values */
+	int fd;
 
 	/* don't even try a .exe */
 	n = strlen(cmd);
@@ -1336,7 +1406,7 @@ static char *path_lookup(const char *cmd, int exe_only)
 {
 	const char *path;
 	char *prog = NULL;
-	int len = strlen(cmd);
+	size_t len = strlen(cmd);
 	int isexe = len >= 4 && !strcasecmp(cmd+len-4, ".exe");
 
 	if (strpbrk(cmd, "/\\"))
@@ -1953,7 +2023,7 @@ char *mingw_getenv(const char *name)
 #define GETENV_MAX_RETAIN 64
 	static char *values[GETENV_MAX_RETAIN];
 	static int value_counter;
-	int len_key, len_value;
+	size_t len_key, len_value;
 	wchar_t *w_key;
 	char *value;
 	wchar_t w_value[32768];
@@ -1965,7 +2035,8 @@ char *mingw_getenv(const char *name)
 	/* We cannot use xcalloc() here because that uses getenv() itself */
 	w_key = calloc(len_key, sizeof(wchar_t));
 	if (!w_key)
-		die("Out of memory, (tried to allocate %u wchar_t's)", len_key);
+		die("Out of memory, (tried to allocate %"PRIuMAX" wchar_t's)",
+			(uintmax_t)len_key);
 	xutftowcs(w_key, name, len_key);
 	/* GetEnvironmentVariableW() only sets the last error upon failure */
 	SetLastError(ERROR_SUCCESS);
@@ -1980,7 +2051,8 @@ char *mingw_getenv(const char *name)
 	/* We cannot use xcalloc() here because that uses getenv() itself */
 	value = calloc(len_value, sizeof(char));
 	if (!value)
-		die("Out of memory, (tried to allocate %u bytes)", len_value);
+		die("Out of memory, (tried to allocate %"PRIuMAX" bytes)",
+			(uintmax_t)len_value);
 	xwcstoutf(value, w_value, len_value);
 
 	/*
@@ -1998,7 +2070,7 @@ char *mingw_getenv(const char *name)
 
 int mingw_putenv(const char *namevalue)
 {
-	int size;
+	size_t size;
 	wchar_t *wide, *equal;
 	BOOL result;
 
@@ -2008,7 +2080,8 @@ int mingw_putenv(const char *namevalue)
 	size = strlen(namevalue) * 2 + 1;
 	wide = calloc(size, sizeof(wchar_t));
 	if (!wide)
-		die("Out of memory, (tried to allocate %u wchar_t's)", size);
+		die("Out of memory, (tried to allocate %" PRIuMAX " wchar_t's)",
+		    (uintmax_t)size);
 	xutftowcs(wide, namevalue, size);
 	equal = wcschr(wide, L'=');
 	if (!equal)
@@ -2148,10 +2221,16 @@ int mingw_accept(int sockfd1, struct sockaddr *sa, socklen_t *sz)
 #undef rename
 int mingw_rename(const char *pold, const char *pnew)
 {
+	static int supports_file_rename_info_ex = 1;
 	DWORD attrs, gle;
 	int tries = 0;
 	wchar_t wpold[MAX_PATH], wpnew[MAX_PATH];
-	if (xutftowcs_path(wpold, pold) < 0 || xutftowcs_path(wpnew, pnew) < 0)
+	int wpnew_len;
+
+	if (xutftowcs_path(wpold, pold) < 0)
+		return -1;
+	wpnew_len = xutftowcs_path(wpnew, pnew);
+	if (wpnew_len < 0)
 		return -1;
 
 	/*
@@ -2162,11 +2241,84 @@ int mingw_rename(const char *pold, const char *pnew)
 		return 0;
 	if (errno != EEXIST)
 		return -1;
+
 repeat:
-	if (MoveFileExW(wpold, wpnew, MOVEFILE_REPLACE_EXISTING))
-		return 0;
+	if (supports_file_rename_info_ex) {
+		/*
+		 * Our minimum required Windows version is still set to Windows
+		 * Vista. We thus have to declare required infrastructure for
+		 * FileRenameInfoEx ourselves until we bump _WIN32_WINNT to
+		 * 0x0A00. Furthermore, we have to handle cases where the
+		 * FileRenameInfoEx call isn't supported yet.
+		 */
+#define FILE_RENAME_FLAG_REPLACE_IF_EXISTS                  0x00000001
+#define FILE_RENAME_FLAG_POSIX_SEMANTICS                    0x00000002
+		FILE_INFO_BY_HANDLE_CLASS FileRenameInfoEx = 22;
+		struct {
+			/*
+			 * This is usually an unnamed union, but that is not
+			 * part of ISO C99. We thus inline the field, as we
+			 * really only care for the Flags field anyway.
+			 */
+			DWORD Flags;
+			HANDLE RootDirectory;
+			DWORD FileNameLength;
+			/*
+			 * The actual structure is defined with a single-character
+			 * flex array so that the structure has to be allocated on
+			 * the heap. As we declare this structure ourselves though
+			 * we can avoid the allocation and define FileName to have
+			 * MAX_PATH bytes.
+			 */
+			WCHAR FileName[MAX_PATH];
+		} rename_info = { 0 };
+		HANDLE old_handle = INVALID_HANDLE_VALUE;
+		BOOL success;
+
+		old_handle = CreateFileW(wpold, DELETE,
+					 FILE_SHARE_WRITE | FILE_SHARE_READ | FILE_SHARE_DELETE,
+					 NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
+		if (old_handle == INVALID_HANDLE_VALUE) {
+			errno = err_win_to_posix(GetLastError());
+			return -1;
+		}
+
+		rename_info.Flags = FILE_RENAME_FLAG_REPLACE_IF_EXISTS |
+				    FILE_RENAME_FLAG_POSIX_SEMANTICS;
+		rename_info.FileNameLength = wpnew_len * sizeof(WCHAR);
+		memcpy(rename_info.FileName, wpnew, wpnew_len * sizeof(WCHAR));
+
+		success = SetFileInformationByHandle(old_handle, FileRenameInfoEx,
+						     &rename_info, sizeof(rename_info));
+		gle = GetLastError();
+		CloseHandle(old_handle);
+		if (success)
+			return 0;
+
+		/*
+		 * When we see ERROR_INVALID_PARAMETER we can assume that the
+		 * current system doesn't support FileRenameInfoEx. Keep us
+		 * from using it in future calls and retry.
+		 */
+		if (gle == ERROR_INVALID_PARAMETER) {
+			supports_file_rename_info_ex = 0;
+			goto repeat;
+		}
+
+		/*
+		 * In theory, we shouldn't get ERROR_ACCESS_DENIED because we
+		 * always open files with FILE_SHARE_DELETE But in practice we
+		 * cannot assume that Git is the only one accessing files, and
+		 * other applications may not set FILE_SHARE_DELETE. So we have
+		 * to retry.
+		 */
+	} else {
+		if (MoveFileExW(wpold, wpnew, MOVEFILE_REPLACE_EXISTING))
+			return 0;
+		gle = GetLastError();
+	}
+
 	/* TODO: translate more errors */
-	gle = GetLastError();
 	if (gle == ERROR_ACCESS_DENIED &&
 	    (attrs = GetFileAttributesW(wpnew)) != INVALID_FILE_ATTRIBUTES) {
 		if (attrs & FILE_ATTRIBUTE_DIRECTORY) {
@@ -2252,7 +2404,7 @@ char *mingw_query_user_email(void)
 	return get_extended_user_info(NameUserPrincipal);
 }
 
-struct passwd *getpwuid(int uid)
+struct passwd *getpwuid(int uid UNUSED)
 {
 	static unsigned initialized;
 	static char user_name[100];
@@ -2304,7 +2456,7 @@ static sig_handler_t timer_fn = SIG_DFL, sigint_fn = SIG_DFL;
  * length to call the signal handler.
  */
 
-static unsigned __stdcall ticktack(void *dummy)
+static unsigned __stdcall ticktack(void *dummy UNUSED)
 {
 	while (WaitForSingleObject(timer_event, timer_interval) == WAIT_TIMEOUT) {
 		mingw_raise(SIGALRM);
@@ -2352,7 +2504,7 @@ static inline int is_timeval_eq(const struct timeval *i1, const struct timeval *
 	return i1->tv_sec == i2->tv_sec && i1->tv_usec == i2->tv_usec;
 }
 
-int setitimer(int type, struct itimerval *in, struct itimerval *out)
+int setitimer(int type UNUSED, struct itimerval *in, struct itimerval *out)
 {
 	static const struct timeval zero;
 	static int atexit_done;
@@ -3082,7 +3234,8 @@ static void maybe_redirect_std_handles(void)
  */
 int wmain(int argc, const wchar_t **wargv)
 {
-	int i, maxlen, exit_status;
+	int i, exit_status;
+	size_t maxlen;
 	char *buffer, **save;
 	const char **argv;
 
diff --git a/compat/mingw.h b/compat/mingw.h
index 27b61284f4..ebfb8ba423 100644
--- a/compat/mingw.h
+++ b/compat/mingw.h
@@ -122,17 +122,17 @@ struct utsname {
  * trivial stubs
  */
 
-static inline int readlink(const char *path, char *buf, size_t bufsiz)
+static inline int readlink(const char *path UNUSED, char *buf UNUSED, size_t bufsiz UNUSED)
 { errno = ENOSYS; return -1; }
-static inline int symlink(const char *oldpath, const char *newpath)
+static inline int symlink(const char *oldpath UNUSED, const char *newpath UNUSED)
 { errno = ENOSYS; return -1; }
-static inline int fchmod(int fildes, mode_t mode)
+static inline int fchmod(int fildes UNUSED, mode_t mode UNUSED)
 { errno = ENOSYS; return -1; }
 #ifndef __MINGW64_VERSION_MAJOR
 static inline pid_t fork(void)
 { errno = ENOSYS; return -1; }
 #endif
-static inline unsigned int alarm(unsigned int seconds)
+static inline unsigned int alarm(unsigned int seconds UNUSED)
 { return 0; }
 static inline int fsync(int fd)
 { return _commit(fd); }
@@ -140,9 +140,9 @@ static inline void sync(void)
 {}
 static inline uid_t getuid(void)
 { return 1; }
-static inline struct passwd *getpwnam(const char *name)
+static inline struct passwd *getpwnam(const char *name UNUSED)
 { return NULL; }
-static inline int fcntl(int fd, int cmd, ...)
+static inline int fcntl(int fd UNUSED, int cmd, ...)
 {
 	if (cmd == F_GETFD || cmd == F_SETFD)
 		return 0;
@@ -151,17 +151,17 @@ static inline int fcntl(int fd, int cmd, ...)
 }
 
 #define sigemptyset(x) (void)0
-static inline int sigaddset(sigset_t *set, int signum)
+static inline int sigaddset(sigset_t *set UNUSED, int signum UNUSED)
 { return 0; }
 #define SIG_BLOCK 0
 #define SIG_UNBLOCK 0
-static inline int sigprocmask(int how, const sigset_t *set, sigset_t *oldset)
+static inline int sigprocmask(int how UNUSED, const sigset_t *set UNUSED, sigset_t *oldset UNUSED)
 { return 0; }
 static inline pid_t getppid(void)
 { return 1; }
 static inline pid_t getpgid(pid_t pid)
 { return pid == 0 ? getpid() : pid; }
-static inline pid_t tcgetpgrp(int fd)
+static inline pid_t tcgetpgrp(int fd UNUSED)
 { return getpid(); }
 
 /*
diff --git a/compat/nedmalloc/nedmalloc.c b/compat/nedmalloc/nedmalloc.c
index 2c0ace7075..145255da43 100644
--- a/compat/nedmalloc/nedmalloc.c
+++ b/compat/nedmalloc/nedmalloc.c
@@ -31,6 +31,8 @@ DEALINGS IN THE SOFTWARE.
 /*#pragma optimize("a", on)*/
 #endif
 
+#pragma GCC diagnostic ignored "-Wunused-parameter"
+
 /*#define FULLSANITYCHECKS*/
 
 #include "nedmalloc.h"
diff --git a/compat/precompose_utf8.c b/compat/precompose_utf8.c
index 0bd5c24250..f7cc7b3be5 100644
--- a/compat/precompose_utf8.c
+++ b/compat/precompose_utf8.c
@@ -4,6 +4,7 @@
  */
 
 #define PRECOMPOSE_UNICODE_C
+#define USE_THE_REPOSITORY_VARIABLE
 
 #include "git-compat-util.h"
 #include "config.h"
diff --git a/compat/regex/regcomp.c b/compat/regex/regcomp.c
index 6c5d455e92..8d93a9b93f 100644
--- a/compat/regex/regcomp.c
+++ b/compat/regex/regcomp.c
@@ -17,6 +17,8 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
+#pragma GCC diagnostic ignored "-Wunused-parameter"
+
 #if defined __TANDEM
  /* This is currently duplicated from git-compat-utils.h */
 # ifdef NO_INTPTR_T
diff --git a/compat/regex/regexec.c b/compat/regex/regexec.c
index e92be5741d..2eeec82f40 100644
--- a/compat/regex/regexec.c
+++ b/compat/regex/regexec.c
@@ -292,7 +292,7 @@ compat_symbol (libc, __compat_regexec, regexec, GLIBC_2_0);
    concerned.
 
    If REGS is not NULL, and BUFP->no_sub is not set, the offsets of the match
-   and all groups is stroed in REGS.  (For the "_2" variants, the offsets are
+   and all groups are stored in REGS.  (For the "_2" variants, the offsets are
    computed relative to the concatenation, not relative to the individual
    strings.)
 
diff --git a/compat/simple-ipc/ipc-shared.c b/compat/simple-ipc/ipc-shared.c
index cb176d966f..d1c21b49bd 100644
--- a/compat/simple-ipc/ipc-shared.c
+++ b/compat/simple-ipc/ipc-shared.c
@@ -16,11 +16,12 @@ int ipc_server_run(const char *path, const struct ipc_server_opts *opts,
 	struct ipc_server_data *server_data = NULL;
 	int ret;
 
-	ret = ipc_server_run_async(&server_data, path, opts,
-				   application_cb, application_data);
+	ret = ipc_server_init_async(&server_data, path, opts,
+				    application_cb, application_data);
 	if (ret)
 		return ret;
 
+	ipc_server_start_async(server_data);
 	ret = ipc_server_await(server_data);
 
 	ipc_server_free(server_data);
diff --git a/compat/simple-ipc/ipc-unix-socket.c b/compat/simple-ipc/ipc-unix-socket.c
index 9b3f2cdf8c..7db3b2a897 100644
--- a/compat/simple-ipc/ipc-unix-socket.c
+++ b/compat/simple-ipc/ipc-unix-socket.c
@@ -328,6 +328,7 @@ struct ipc_server_data {
 	int back_pos;
 	int front_pos;
 
+	int started;
 	int shutdown_requested;
 	int is_stopped;
 };
@@ -712,7 +713,7 @@ static int accept_thread__wait_for_connection(
  * Block SIGPIPE in this thread for the life of the thread.  This
  * avoids any stray SIGPIPE signals when closing pipe fds under
  * extremely heavy loads (such as when the fifo queue is full and we
- * drop incomming connections).
+ * drop incoming connections).
  */
 static void *accept_thread_proc(void *_accept_thread_data)
 {
@@ -824,10 +825,10 @@ static int setup_listener_socket(
 /*
  * Start IPC server in a pool of background threads.
  */
-int ipc_server_run_async(struct ipc_server_data **returned_server_data,
-			 const char *path, const struct ipc_server_opts *opts,
-			 ipc_server_application_cb *application_cb,
-			 void *application_data)
+int ipc_server_init_async(struct ipc_server_data **returned_server_data,
+			  const char *path, const struct ipc_server_opts *opts,
+			  ipc_server_application_cb *application_cb,
+			  void *application_data)
 {
 	struct unix_ss_socket *server_socket = NULL;
 	struct ipc_server_data *server_data;
@@ -888,6 +889,12 @@ int ipc_server_run_async(struct ipc_server_data **returned_server_data,
 	server_data->accept_thread->fd_send_shutdown = sv[0];
 	server_data->accept_thread->fd_wait_shutdown = sv[1];
 
+	/*
+	 * Hold work-available mutex so that no work can start until
+	 * we unlock it.
+	 */
+	pthread_mutex_lock(&server_data->work_available_mutex);
+
 	if (pthread_create(&server_data->accept_thread->pthread_id, NULL,
 			   accept_thread_proc, server_data->accept_thread))
 		die_errno(_("could not start accept_thread '%s'"), path);
@@ -918,6 +925,15 @@ int ipc_server_run_async(struct ipc_server_data **returned_server_data,
 	return 0;
 }
 
+void ipc_server_start_async(struct ipc_server_data *server_data)
+{
+	if (!server_data || server_data->started)
+		return;
+
+	server_data->started = 1;
+	pthread_mutex_unlock(&server_data->work_available_mutex);
+}
+
 /*
  * Gently tell the IPC server treads to shutdown.
  * Can be run on any thread.
@@ -933,7 +949,9 @@ int ipc_server_stop_async(struct ipc_server_data *server_data)
 
 	trace2_region_enter("ipc-server", "server-stop-async", NULL);
 
-	pthread_mutex_lock(&server_data->work_available_mutex);
+	/* If we haven't started yet, we are already holding lock. */
+	if (server_data->started)
+		pthread_mutex_lock(&server_data->work_available_mutex);
 
 	server_data->shutdown_requested = 1;
 
diff --git a/compat/simple-ipc/ipc-win32.c b/compat/simple-ipc/ipc-win32.c
index 8bfe51248e..a8fc812adf 100644
--- a/compat/simple-ipc/ipc-win32.c
+++ b/compat/simple-ipc/ipc-win32.c
@@ -371,6 +371,9 @@ struct ipc_server_data {
 	HANDLE hEventStopRequested;
 	struct ipc_server_thread_data *thread_list;
 	int is_stopped;
+
+	pthread_mutex_t startup_barrier;
+	int started;
 };
 
 enum connect_result {
@@ -526,6 +529,16 @@ static int use_connection(struct ipc_server_thread_data *server_thread_data)
 	return ret;
 }
 
+static void wait_for_startup_barrier(struct ipc_server_data *server_data)
+{
+	/*
+	 * Temporarily hold the startup_barrier mutex before starting,
+	 * which lets us know that it's OK to start serving requests.
+	 */
+	pthread_mutex_lock(&server_data->startup_barrier);
+	pthread_mutex_unlock(&server_data->startup_barrier);
+}
+
 /*
  * Thread proc for an IPC server worker thread.  It handles a series of
  * connections from clients.  It cleans and reuses the hPipe between each
@@ -550,6 +563,8 @@ static void *server_thread_proc(void *_server_thread_data)
 	memset(&oConnect, 0, sizeof(oConnect));
 	oConnect.hEvent = hEventConnected;
 
+	wait_for_startup_barrier(server_thread_data->server_data);
+
 	for (;;) {
 		cr = wait_for_connection(server_thread_data, &oConnect);
 
@@ -752,10 +767,10 @@ static HANDLE create_new_pipe(wchar_t *wpath, int is_first)
 	return hPipe;
 }
 
-int ipc_server_run_async(struct ipc_server_data **returned_server_data,
-			 const char *path, const struct ipc_server_opts *opts,
-			 ipc_server_application_cb *application_cb,
-			 void *application_data)
+int ipc_server_init_async(struct ipc_server_data **returned_server_data,
+			  const char *path, const struct ipc_server_opts *opts,
+			  ipc_server_application_cb *application_cb,
+			  void *application_data)
 {
 	struct ipc_server_data *server_data;
 	wchar_t wpath[MAX_PATH];
@@ -787,6 +802,13 @@ int ipc_server_run_async(struct ipc_server_data **returned_server_data,
 	strbuf_addstr(&server_data->buf_path, path);
 	wcscpy(server_data->wpath, wpath);
 
+	/*
+	 * Hold the startup_barrier lock so that no threads will progress
+	 * until ipc_server_start_async() is called.
+	 */
+	pthread_mutex_init(&server_data->startup_barrier, NULL);
+	pthread_mutex_lock(&server_data->startup_barrier);
+
 	if (nr_threads < 1)
 		nr_threads = 1;
 
@@ -837,6 +859,15 @@ int ipc_server_run_async(struct ipc_server_data **returned_server_data,
 	return 0;
 }
 
+void ipc_server_start_async(struct ipc_server_data *server_data)
+{
+	if (!server_data || server_data->started)
+		return;
+
+	server_data->started = 1;
+	pthread_mutex_unlock(&server_data->startup_barrier);
+}
+
 int ipc_server_stop_async(struct ipc_server_data *server_data)
 {
 	if (!server_data)
@@ -850,6 +881,13 @@ int ipc_server_stop_async(struct ipc_server_data *server_data)
 	 * We DO NOT attempt to force them to drop an active connection.
 	 */
 	SetEvent(server_data->hEventStopRequested);
+
+	/*
+	 * If we haven't yet told the threads they are allowed to run,
+	 * do so now, so they can receive the shutdown event.
+	 */
+	ipc_server_start_async(server_data);
+
 	return 0;
 }
 
@@ -900,5 +938,7 @@ void ipc_server_free(struct ipc_server_data *server_data)
 		free(std);
 	}
 
+	pthread_mutex_destroy(&server_data->startup_barrier);
+
 	free(server_data);
 }
diff --git a/compat/stub/procinfo.c b/compat/stub/procinfo.c
index 12c0a23c9e..3168cd5714 100644
--- a/compat/stub/procinfo.c
+++ b/compat/stub/procinfo.c
@@ -6,6 +6,6 @@
  * Stub. See sample implementations in compat/linux/procinfo.c and
  * compat/win32/trace2_win32_process_info.c.
  */
-void trace2_collect_process_info(enum trace2_process_info_reason reason)
+void trace2_collect_process_info(enum trace2_process_info_reason reason UNUSED)
 {
 }
diff --git a/compat/terminal.c b/compat/terminal.c
index 0afda730f2..d54efa1c5d 100644
--- a/compat/terminal.c
+++ b/compat/terminal.c
@@ -594,7 +594,7 @@ void restore_term(void)
 {
 }
 
-char *git_terminal_prompt(const char *prompt, int echo)
+char *git_terminal_prompt(const char *prompt, int echo UNUSED)
 {
 	return getpass(prompt);
 }
diff --git a/compat/vcbuild/include/unistd.h b/compat/vcbuild/include/unistd.h
index 3a959d124c..a261a925b7 100644
--- a/compat/vcbuild/include/unistd.h
+++ b/compat/vcbuild/include/unistd.h
@@ -14,7 +14,11 @@ typedef _mode_t	mode_t;
 
 #ifndef _SSIZE_T_
 #define _SSIZE_T_
+#ifdef _WIN64
+typedef __int64 _ssize_t;
+#else
 typedef long _ssize_t;
+#endif /* _WIN64 */
 
 #ifndef	_OFF_T_
 #define	_OFF_T_
diff --git a/compat/win32/headless.c b/compat/win32/headless.c
index 8b00dfe3bd..11392a0b9a 100644
--- a/compat/win32/headless.c
+++ b/compat/win32/headless.c
@@ -11,6 +11,8 @@
 #include <stdlib.h>
 #include <wchar.h>
 
+#pragma GCC diagnostic ignored "-Wunused-parameter"
+
 /*
  * If `dir` contains the path to a Git exec directory, extend `PATH` to
  * include the corresponding `bin/` directory (which is where all those
diff --git a/compat/win32/path-utils.c b/compat/win32/path-utils.c
index b658ca3f81..966ef779b9 100644
--- a/compat/win32/path-utils.c
+++ b/compat/win32/path-utils.c
@@ -1,3 +1,5 @@
+#define USE_THE_REPOSITORY_VARIABLE
+
 #include "../../git-compat-util.h"
 #include "../../environment.h"
 
diff --git a/compat/win32/pthread.c b/compat/win32/pthread.c
index 85f8f7920c..58980a529c 100644
--- a/compat/win32/pthread.c
+++ b/compat/win32/pthread.c
@@ -21,7 +21,7 @@ static unsigned __stdcall win32_start_routine(void *arg)
 	return 0;
 }
 
-int pthread_create(pthread_t *thread, const void *unused,
+int pthread_create(pthread_t *thread, const void *attr UNUSED,
 		   void *(*start_routine)(void *), void *arg)
 {
 	thread->arg = arg;
diff --git a/compat/win32/pthread.h b/compat/win32/pthread.h
index cc3221cb2c..e2b5c4f64c 100644
--- a/compat/win32/pthread.h
+++ b/compat/win32/pthread.h
@@ -18,7 +18,7 @@
  */
 #define pthread_mutex_t CRITICAL_SECTION
 
-static inline int return_0(int i) {
+static inline int return_0(int i UNUSED) {
 	return 0;
 }
 #define pthread_mutex_init(a,b) return_0((InitializeCriticalSection((a)), 0))
@@ -70,7 +70,7 @@ static inline void NORETURN pthread_exit(void *ret)
 }
 
 typedef DWORD pthread_key_t;
-static inline int pthread_key_create(pthread_key_t *keyp, void (*destructor)(void *value))
+static inline int pthread_key_create(pthread_key_t *keyp, void (*destructor)(void *value) UNUSED)
 {
 	return (*keyp = TlsAlloc()) == TLS_OUT_OF_INDEXES ? EAGAIN : 0;
 }
diff --git a/compat/win32/syslog.c b/compat/win32/syslog.c
index 0af18d8882..4e4794743a 100644
--- a/compat/win32/syslog.c
+++ b/compat/win32/syslog.c
@@ -2,7 +2,7 @@
 
 static HANDLE ms_eventlog;
 
-void openlog(const char *ident, int logopt, int facility)
+void openlog(const char *ident, int logopt UNUSED, int facility UNUSED)
 {
 	if (ms_eventlog)
 		return;
diff --git a/compat/win32mmap.c b/compat/win32mmap.c
index 519d51f2b6..a4ab4cb939 100644
--- a/compat/win32mmap.c
+++ b/compat/win32mmap.c
@@ -40,7 +40,7 @@ void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t of
 	return MAP_FAILED;
 }
 
-int git_munmap(void *start, size_t length)
+int git_munmap(void *start, size_t length UNUSED)
 {
 	return !UnmapViewOfFile(start);
 }
diff --git a/compat/winansi.c b/compat/winansi.c
index 575813bde8..1b3f916b9f 100644
--- a/compat/winansi.c
+++ b/compat/winansi.c
@@ -340,7 +340,7 @@ enum {
 	TEXT = 0, ESCAPE = 033, BRACKET = '['
 };
 
-static DWORD WINAPI console_thread(LPVOID unused)
+static DWORD WINAPI console_thread(LPVOID data UNUSED)
 {
 	unsigned char buffer[BUFFER_SIZE];
 	DWORD bytes;