Make core.sharedRepository work under cygwin 1.7

When core.sharedRepository is used, set_shared_perm() in path.c
needs lstat() to return the correct POSIX permissions.

The default for cygwin is core.ignoreCygwinFSTricks = false, which
means that the fast implementation in do_stat() is used instead of
lstat().

lstat() under cygwin uses the Windows security model to implement
POSIX-like permissions.  The user, group or everyone bits can be set
individually.

do_stat() simplifes the file permission bits, and may return a wrong
value.  The read-only attribute of a file is used to calculate the
permissions, resulting in either rw-r--r-- or r--r--r--

One effect of the simplified do_stat() is that t1301 fails.

Add a function cygwin_get_st_mode_bits() which returns the POSIX
permissions.  When not compiling for cygwin, true_mode_bits() in
path.c is used.

Side note:

t1301 passes under cygwin 1.5.

The "user write" bit is synchronized with the "read only" attribute
of a file:

$ chmod 444 x
$ attrib x
A    R     C:\temp\pt\x

cygwin 1.7 would show
A          C:\temp\pt\x

Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/compat/cygwin.c b/compat/cygwin.c
index 5428858875a20b89411d3662e777586d9d798fab..871b41d23a7471724a0446ff3333b577a175c579 100644 (file)
--- a/compat/cygwin.c
+++ b/compat/cygwin.c
@@ -1,3 +1,4 @@
+#define CYGWIN_C
 #define WIN32_LEAN_AND_MEAN
 #ifdef CYGWIN_V15_WIN32API
 #include "../git-compat-util.h"
@@ -10,6 +11,18 @@
 #endif
 #include "../cache.h" /* to read configuration */
 
+/*
+ * Return POSIX permission bits, regardless of core.ignorecygwinfstricks
+ */
+int cygwin_get_st_mode_bits(const char *path, int *mode)
+{
+       struct stat st;
+       if (lstat(path, &st) < 0)
+               return -1;
+       *mode = st.st_mode;
+       return 0;
+}
+
 static inline void filetime_to_timespec(const FILETIME *ft, struct timespec *ts)
 {
        long long winTime = ((long long)ft->dwHighDateTime << 32) +

diff --git a/compat/cygwin.h b/compat/cygwin.h
index a3229f5b4fbb819ba1beabcf560725e80ad51bb4..c04965a2e0e259d3bded51730f699bde5c4262e6 100644 (file)
--- a/compat/cygwin.h
+++ b/compat/cygwin.h
@@ -4,6 +4,11 @@
 typedef int (*stat_fn_t)(const char*, struct stat*);
 extern stat_fn_t cygwin_stat_fn;
 extern stat_fn_t cygwin_lstat_fn;
+int cygwin_get_st_mode_bits(const char *path, int *mode);
 
+#define get_st_mode_bits(p,m) cygwin_get_st_mode_bits((p),(m))
+#ifndef CYGWIN_C
+/* cygwin.c needs the original lstat() */
 #define stat(path, buf) (*cygwin_stat_fn)(path, buf)
 #define lstat(path, buf) (*cygwin_lstat_fn)(path, buf)
+#endif

diff --git a/git-compat-util.h b/git-compat-util.h
index 90e037203879f6ba91403ae5371f18910206b580..cde442fb5f47cd13757e09ae435963bc061db083 100644 (file)
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -163,6 +163,7 @@
 typedef long intptr_t;
 typedef unsigned long uintptr_t;
 #endif
+int get_st_mode_bits(const char *path, int *mode);
 #if defined(__CYGWIN__)
 #undef _XOPEN_SOURCE
 #include <grp.h>

diff --git a/path.c b/path.c
index d3d3f8b8ad75b9817df3014296aabc34b6a4eb14..2fdccc2f18367399b8247ee79ec8bf4934f596cb 100644 (file)
--- a/path.c
+++ b/path.c
@@ -14,6 +14,22 @@
 #include "strbuf.h"
 #include "string-list.h"
 
+#ifndef get_st_mode_bits
+/*
+ * The replacement lstat(2) we use on Cygwin is incomplete and
+ * may return wrong permission bits. Most of the time we do not care,
+ * but the callsites of this wrapper do care.
+ */
+int get_st_mode_bits(const char *path, int *mode)
+{
+       struct stat st;
+       if (lstat(path, &st) < 0)
+               return -1;
+       *mode = st.st_mode;
+       return 0;
+}
+#endif
+
 static char bad_path[] = "/bad-path/";
 
 static char *get_pathname(void)
@@ -391,7 +407,6 @@ const char *enter_repo(const char *path, int strict)
 
 int set_shared_perm(const char *path, int mode)
 {
-       struct stat st;
        int tweak, shared, orig_mode;
 
        if (!shared_repository) {
@@ -400,9 +415,8 @@ int set_shared_perm(const char *path, int mode)
                return 0;
        }
        if (!mode) {
-               if (lstat(path, &st) < 0)
+               if (get_st_mode_bits(path, &mode) < 0)
                        return -1;
-               mode = st.st_mode;
                orig_mode = mode;
        } else
                orig_mode = 0;