1 files changed, 174 insertions, 15 deletions

diff --git a/compat/mingw.c b/compat/mingw.c
index a67872b..81ef242 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -5,6 +5,7 @@
 #include "../strbuf.h"
 #include "../run-command.h"
 #include "../cache.h"
+#include "win32/lazyload.h"
 
 #define HCAST(type, handle) ((type)(intptr_t)handle)
 
@@ -202,6 +203,31 @@ static int ask_yes_no_if_possible(const char *format, ...)
 	}
 }
 
+/* Normalizes NT paths as returned by some low-level APIs. */
+static wchar_t *normalize_ntpath(wchar_t *wbuf)
+{
+	int i;
+	/* fix absolute path prefixes */
+	if (wbuf[0] == '\\') {
+		/* strip NT namespace prefixes */
+		if (!wcsncmp(wbuf, L"\\??\\", 4) ||
+		    !wcsncmp(wbuf, L"\\\\?\\", 4))
+			wbuf += 4;
+		else if (!wcsnicmp(wbuf, L"\\DosDevices\\", 12))
+			wbuf += 12;
+		/* replace remaining '...UNC\' with '\\' */
+		if (!wcsnicmp(wbuf, L"UNC\\", 4)) {
+			wbuf += 2;
+			*wbuf = '\\';
+		}
+	}
+	/* convert backslashes to slashes */
+	for (i = 0; wbuf[i]; i++)
+		if (wbuf[i] == '\\')
+			wbuf[i] = '/';
+	return wbuf;
+}
+
 int mingw_unlink(const char *pathname)
 {
 	int ret, tries = 0;
@@ -341,12 +367,74 @@ int mingw_mkdir(const char *path, int mode)
 	return ret;
 }
 
+/*
+ * Calling CreateFile() using FILE_APPEND_DATA and without FILE_WRITE_DATA
+ * is documented in [1] as opening a writable file handle in append mode.
+ * (It is believed that) this is atomic since it is maintained by the
+ * kernel unlike the O_APPEND flag which is racily maintained by the CRT.
+ *
+ * [1] https://docs.microsoft.com/en-us/windows/desktop/fileio/file-access-rights-constants
+ *
+ * This trick does not appear to work for named pipes.  Instead it creates
+ * a named pipe client handle that cannot be written to.  Callers should
+ * just use the regular _wopen() for them.  (And since client handle gets
+ * bound to a unique server handle, it isn't really an issue.)
+ */
+static int mingw_open_append(wchar_t const *wfilename, int oflags, ...)
+{
+	HANDLE handle;
+	int fd;
+	DWORD create = (oflags & O_CREAT) ? OPEN_ALWAYS : OPEN_EXISTING;
+
+	/* only these flags are supported */
+	if ((oflags & ~O_CREAT) != (O_WRONLY | O_APPEND))
+		return errno = ENOSYS, -1;
+
+	/*
+	 * FILE_SHARE_WRITE is required to permit child processes
+	 * to append to the file.
+	 */
+	handle = CreateFileW(wfilename, FILE_APPEND_DATA,
+			FILE_SHARE_WRITE | FILE_SHARE_READ,
+			NULL, create, FILE_ATTRIBUTE_NORMAL, NULL);
+	if (handle == INVALID_HANDLE_VALUE)
+		return errno = err_win_to_posix(GetLastError()), -1;
+
+	/*
+	 * No O_APPEND here, because the CRT uses it only to reset the
+	 * file pointer to EOF before each write(); but that is not
+	 * necessary (and may lead to races) for a file created with
+	 * FILE_APPEND_DATA.
+	 */
+	fd = _open_osfhandle((intptr_t)handle, 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?
+ */
+static int is_local_named_pipe_path(const char *filename)
+{
+	return (is_dir_sep(filename[0]) &&
+		is_dir_sep(filename[1]) &&
+		filename[2] == '.'  &&
+		is_dir_sep(filename[3]) &&
+		!strncasecmp(filename+4, "pipe", 4) &&
+		is_dir_sep(filename[8]) &&
+		filename[9]);
+}
+
 int mingw_open (const char *filename, int oflags, ...)
 {
+	typedef int (*open_fn_t)(wchar_t const *wfilename, int oflags, ...);
 	va_list args;
 	unsigned mode;
 	int fd;
 	wchar_t wfilename[MAX_PATH];
+	open_fn_t open_fn;
 
 	va_start(args, oflags);
 	mode = va_arg(args, int);
@@ -355,9 +443,14 @@ int mingw_open (const char *filename, int oflags, ...)
 	if (filename && !strcmp(filename, "/dev/null"))
 		filename = "nul";
 
+	if ((oflags & O_APPEND) && !is_local_named_pipe_path(filename))
+		open_fn = mingw_open_append;
+	else
+		open_fn = _wopen;
+
 	if (xutftowcs_path(wfilename, filename) < 0)
 		return -1;
-	fd = _wopen(wfilename, oflags, mode);
+	fd = open_fn(wfilename, oflags, mode);
 
 	if (fd < 0 && (oflags & O_ACCMODE) != O_RDONLY && errno == EACCES) {
 		DWORD attrs = GetFileAttributesW(wfilename);
@@ -375,7 +468,7 @@ int mingw_open (const char *filename, int oflags, ...)
 		 * CREATE_ALWAYS flag of CreateFile()).
 		 */
 		if (fd < 0 && errno == EACCES)
-			fd = _wopen(wfilename, oflags & ~O_CREAT, mode);
+			fd = open_fn(wfilename, oflags & ~O_CREAT, mode);
 		if (fd >= 0 && set_hidden_flag(wfilename, 1))
 			warning("could not mark '%s' as hidden.", filename);
 	}
@@ -850,8 +943,29 @@ struct tm *localtime_r(const time_t *timep, struct tm *result)
 
 char *mingw_getcwd(char *pointer, int len)
 {
-	wchar_t wpointer[MAX_PATH];
-	if (!_wgetcwd(wpointer, ARRAY_SIZE(wpointer)))
+	wchar_t cwd[MAX_PATH], wpointer[MAX_PATH];
+	DWORD ret = GetCurrentDirectoryW(ARRAY_SIZE(cwd), cwd);
+
+	if (!ret || ret >= ARRAY_SIZE(cwd)) {
+		errno = ret ? ENAMETOOLONG : err_win_to_posix(GetLastError());
+		return NULL;
+	}
+	ret = GetLongPathNameW(cwd, wpointer, ARRAY_SIZE(wpointer));
+	if (!ret && GetLastError() == ERROR_ACCESS_DENIED) {
+		HANDLE hnd = CreateFileW(cwd, 0,
+			FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL,
+			OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL);
+		if (hnd == INVALID_HANDLE_VALUE)
+			return NULL;
+		ret = GetFinalPathNameByHandleW(hnd, wpointer, ARRAY_SIZE(wpointer), 0);
+		CloseHandle(hnd);
+		if (!ret || ret >= ARRAY_SIZE(wpointer))
+			return NULL;
+		if (xwcstoutf(pointer, normalize_ntpath(wpointer), len) < 0)
+			return NULL;
+		return pointer;
+	}
+	if (!ret || ret >= ARRAY_SIZE(wpointer))
 		return NULL;
 	if (xwcstoutf(pointer, wpointer, len) < 0)
 		return NULL;
@@ -1510,7 +1624,8 @@ static void ensure_socket_initialization(void)
 			WSAGetLastError());
 
 	for (name = libraries; *name; name++) {
-		ipv6_dll = LoadLibrary(*name);
+		ipv6_dll = LoadLibraryExA(*name, NULL,
+					  LOAD_LIBRARY_SEARCH_SYSTEM32);
 		if (!ipv6_dll)
 			continue;
 
@@ -1731,18 +1846,63 @@ int mingw_getpagesize(void)
 	return si.dwAllocationGranularity;
 }
 
+/* See https://msdn.microsoft.com/en-us/library/windows/desktop/ms724435.aspx */
+enum EXTENDED_NAME_FORMAT {
+	NameDisplay = 3,
+	NameUserPrincipal = 8
+};
+
+static char *get_extended_user_info(enum EXTENDED_NAME_FORMAT type)
+{
+	DECLARE_PROC_ADDR(secur32.dll, BOOL, GetUserNameExW,
+		enum EXTENDED_NAME_FORMAT, LPCWSTR, PULONG);
+	static wchar_t wbuffer[1024];
+	DWORD len;
+
+	if (!INIT_PROC_ADDR(GetUserNameExW))
+		return NULL;
+
+	len = ARRAY_SIZE(wbuffer);
+	if (GetUserNameExW(type, wbuffer, &len)) {
+		char *converted = xmalloc((len *= 3));
+		if (xwcstoutf(converted, wbuffer, len) >= 0)
+			return converted;
+		free(converted);
+	}
+
+	return NULL;
+}
+
+char *mingw_query_user_email(void)
+{
+	return get_extended_user_info(NameUserPrincipal);
+}
+
 struct passwd *getpwuid(int uid)
 {
+	static unsigned initialized;
 	static char user_name[100];
-	static struct passwd p;
+	static struct passwd *p;
+	DWORD len;
 
-	DWORD len = sizeof(user_name);
-	if (!GetUserName(user_name, &len))
+	if (initialized)
+		return p;
+
+	len = sizeof(user_name);
+	if (!GetUserName(user_name, &len)) {
+		initialized = 1;
 		return NULL;
-	p.pw_name = user_name;
-	p.pw_gecos = "unknown";
-	p.pw_dir = NULL;
-	return &p;
+	}
+
+	p = xmalloc(sizeof(*p));
+	p->pw_name = user_name;
+	p->pw_gecos = get_extended_user_info(NameDisplay);
+	if (!p->pw_gecos)
+		p->pw_gecos = "unknown";
+	p->pw_dir = NULL;
+
+	initialized = 1;
+	return p;
 }
 
 static HANDLE timer_event;
@@ -2221,7 +2381,7 @@ void mingw_startup(void)
 		die_startup();
 
 	/* determine size of argv and environ conversion buffer */
-	maxlen = wcslen(_wpgmptr);
+	maxlen = wcslen(wargv[0]);
 	for (i = 1; i < argc; i++)
 		maxlen = max(maxlen, wcslen(wargv[i]));
 	for (i = 0; wenv[i]; i++)
@@ -2241,8 +2401,7 @@ void mingw_startup(void)
 	buffer = malloc_startup(maxlen);
 
 	/* convert command line arguments and environment to UTF-8 */
-	__argv[0] = wcstoutfdup_startup(buffer, _wpgmptr, maxlen);
-	for (i = 1; i < argc; i++)
+	for (i = 0; i < argc; i++)
 		__argv[i] = wcstoutfdup_startup(buffer, wargv[i], maxlen);
 	for (i = 0; wenv[i]; i++)
 		environ[i] = wcstoutfdup_startup(buffer, wenv[i], maxlen);