win32: use our own dirent.h

The mingw-runtime implemenation of opendir, readdir and closedir
sets errno to 0 on success, something that POSIX explicitly
forbids. 3ba7a06 ("A loose object is not corrupt if it cannot be
read due to EMFILE") introduce a dependency on this behaviour,
leading to a broken "git clone" on Windows.

compat/mingw.c contains an implementation of readdir, and
compat/msvc.c contains implementations of opendir and closedir.

Move these to compat/win32/dirent.[ch], and change to our own DIR
structure at the same time.

This provides a generic Win32-implementation of opendir, readdir
and closedir which works on both MinGW and MSVC and does not reset
errno, and as a result git clone is working again on Windows.

Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: kusma

Makefile

@@ -499,6 +499,7 @@ LIB_H += compat/mingw.h
 LIB_H += compat/win32/pthread.h
 LIB_H += compat/win32/syslog.h
 LIB_H += compat/win32/sys/poll.h
+LIB_H += compat/win32/dirent.h
 LIB_H += csum-file.h
 LIB_H += decorate.h
 LIB_H += delta.h
@@ -1084,7 +1085,9 @@ ifeq ($(uname_S),Windows)
 	AR = compat/vcbuild/scripts/lib.pl
 	CFLAGS =
 	BASIC_CFLAGS = -nologo -I. -I../zlib -Icompat/vcbuild -Icompat/vcbuild/include -DWIN32 -D_CONSOLE -DHAVE_STRING_H -D_CRT_SECURE_NO_WARNINGS -D_CRT_NONSTDC_NO_DEPRECATE
-	COMPAT_OBJS = compat/msvc.o compat/fnmatch/fnmatch.o compat/winansi.o compat/win32/pthread.o compat/win32/syslog.o compat/win32/sys/poll.o
+	COMPAT_OBJS = compat/msvc.o compat/fnmatch/fnmatch.o compat/winansi.o \
+		compat/win32/pthread.o compat/win32/syslog.o \
+		compat/win32/sys/poll.o compat/win32/dirent.o
 	COMPAT_CFLAGS = -D__USE_MINGW_ACCESS -DNOGDI -DHAVE_STRING_H -DHAVE_ALLOCA_H -Icompat -Icompat/fnmatch -Icompat/regex -Icompat/fnmatch -Icompat/win32 -DSTRIP_EXTENSION=\".exe\"
 	BASIC_LDFLAGS = -IGNORE:4217 -IGNORE:4049 -NOLOGO -SUBSYSTEM:CONSOLE -NODEFAULTLIB:MSVCRT.lib
 	EXTLIBS = advapi32.lib shell32.lib wininet.lib ws2_32.lib
@@ -1137,7 +1140,7 @@ ifneq (,$(findstring MINGW,$(uname_S)))
 	COMPAT_CFLAGS += -DSTRIP_EXTENSION=\".exe\"
 	COMPAT_OBJS += compat/mingw.o compat/fnmatch/fnmatch.o compat/winansi.o \
 		compat/win32/pthread.o compat/win32/syslog.o \
-		compat/win32/sys/poll.o
+		compat/win32/sys/poll.o compat/win32/dirent.o
 	EXTLIBS += -lws2_32
 	PTHREAD_LIBS =
 	X = .exe

compat/mingw.c

@@ -1564,63 +1564,3 @@ pid_t waitpid(pid_t pid, int *status, unsigned options)
 	errno = EINVAL;
 	return -1;
 }
-
-#ifndef NO_MINGW_REPLACE_READDIR
-/* MinGW readdir implementation to avoid extra lstats for Git */
-struct mingw_DIR
-{
-	struct _finddata_t	dd_dta;		/* disk transfer area for this dir */
-	struct mingw_dirent	dd_dir;		/* Our own implementation, including d_type */
-	long			dd_handle;	/* _findnext handle */
-	int			dd_stat; 	/* 0 = next entry to read is first entry, -1 = off the end, positive = 0 based index of next entry */
-	char			dd_name[1]; 	/* given path for dir with search pattern (struct is extended) */
-};
-
-struct dirent *mingw_readdir(DIR *dir)
-{
-	WIN32_FIND_DATAA buf;
-	HANDLE handle;
-	struct mingw_DIR *mdir = (struct mingw_DIR*)dir;
-
-	if (!dir || !dir->dd_handle) {
-		errno = EBADF; /* No set_errno for mingw */
-		return NULL;
-	}
-
-	if (dir->dd_handle == (long)INVALID_HANDLE_VALUE && dir->dd_stat == 0)
-	{
-		DWORD lasterr;
-		handle = FindFirstFileA(dir->dd_name, &buf);
-		lasterr = GetLastError();
-		dir->dd_handle = (long)handle;
-		if (handle == INVALID_HANDLE_VALUE && (lasterr != ERROR_NO_MORE_FILES)) {
-			errno = err_win_to_posix(lasterr);
-			return NULL;
-		}
-	} else if (dir->dd_handle == (long)INVALID_HANDLE_VALUE) {
-		return NULL;
-	} else if (!FindNextFileA((HANDLE)dir->dd_handle, &buf)) {
-		DWORD lasterr = GetLastError();
-		FindClose((HANDLE)dir->dd_handle);
-		dir->dd_handle = (long)INVALID_HANDLE_VALUE;
-		/* POSIX says you shouldn't set errno when readdir can't
-		   find any more files; so, if another error we leave it set. */
-		if (lasterr != ERROR_NO_MORE_FILES)
-			errno = err_win_to_posix(lasterr);
-		return NULL;
-	}
-
-	/* We get here if `buf' contains valid data.  */
-	strcpy(dir->dd_dir.d_name, buf.cFileName);
-	++dir->dd_stat;
-
-	/* Set file type, based on WIN32_FIND_DATA */
-	mdir->dd_dir.d_type = 0;
-	if (buf.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
-		mdir->dd_dir.d_type |= DT_DIR;
-	else
-		mdir->dd_dir.d_type |= DT_REG;
-
-	return (struct dirent*)&dir->dd_dir;
-}
-#endif // !NO_MINGW_REPLACE_READDIR

compat/mingw.h

@@ -319,35 +319,6 @@ int main(int argc, const char **argv) \
 } \
 static int mingw_main(c,v)
 
-#ifndef NO_MINGW_REPLACE_READDIR
-/*
- * A replacement of readdir, to ensure that it reads the file type at
- * the same time. This avoid extra unneeded lstats in git on MinGW
- */
-#undef DT_UNKNOWN
-#undef DT_DIR
-#undef DT_REG
-#undef DT_LNK
-#define DT_UNKNOWN	0
-#define DT_DIR		1
-#define DT_REG		2
-#define DT_LNK		3
-
-struct mingw_dirent
-{
-	long		d_ino;			/* Always zero. */
-	union {
-		unsigned short	d_reclen;	/* Always zero. */
-		unsigned char   d_type;		/* Reimplementation adds this */
-	};
-	unsigned short	d_namlen;		/* Length of name in d_name. */
-	char		d_name[FILENAME_MAX];	/* File name. */
-};
-#define dirent mingw_dirent
-#define readdir(x) mingw_readdir(x)
-struct dirent *mingw_readdir(DIR *dir);
-#endif // !NO_MINGW_REPLACE_READDIR
-
 /*
  * Used by Pthread API implementation for Windows
  */

compat/msvc.c

@@ -3,56 +3,4 @@
 #include <conio.h>
 #include "../strbuf.h"
 
-DIR *opendir(const char *name)
-{
-	DWORD attrs = GetFileAttributes(name);
-	int len;
-	DIR *p;
-
-	/* check for valid path */
-	if (attrs == INVALID_FILE_ATTRIBUTES) {
-		errno = ENOENT;
-		return NULL;
-	}
-
-	/* check if it's a directory */
-	if (!(attrs & FILE_ATTRIBUTE_DIRECTORY)) {
-		errno = ENOTDIR;
-		return NULL;
-	}
-
-	/* check that the pattern won't be too long for FindFirstFileA */
-	len = strlen(name);
-	if (is_dir_sep(name[len - 1]))
-		len--;
-	if (len + 2 >= MAX_PATH) {
-		errno = ENAMETOOLONG;
-		return NULL;
-	}
-
-	p = malloc(sizeof(DIR) + len + 2);
-	if (!p)
-		return NULL;
-
-	memset(p, 0, sizeof(DIR) + len + 2);
-	strcpy(p->dd_name, name);
-	p->dd_name[len] = '/';
-	p->dd_name[len+1] = '*';
-
-	p->dd_handle = (long)INVALID_HANDLE_VALUE;
-	return p;
-}
-int closedir(DIR *dir)
-{
-	if (!dir) {
-		errno = EBADF;
-		return -1;
-	}
-
-	if (dir->dd_handle != (long)INVALID_HANDLE_VALUE)
-		FindClose((HANDLE)dir->dd_handle);
-	free(dir);
-	return 0;
-}
-
 #include "mingw.c"