[patch] munmap-before-rename, cygwin need

I found that mmap() works on cygwin, but needs a patch.
On Cygwin, rename() fails if target file has active mmap().
The patch below adds  munmap() before rename().

If you excuse me for posting not in git-generated format
(I did not yet completely make git working on my cygwin).
I'm adding the copy as attachment, I'm afraid the mailer
may interfere with spaces ?

Yakov Lerner

Makefile     |    5 +++++
cache.h      |    1 +
index.c      |    3 +++
read-cache.c |   14 ++++++++++++++

--- Makefile.000 2006-05-07 22:32:04.000000000 +0300
+++ Makefile 2006-05-07 22:30:38.000000000 +0300

@@ -46,6 +46,9 @@

#
# Define NO_MMAP if you want to avoid mmap.
#
+# Define MUMNAP_BEFORE_RENAME if munmap() on target file is required
+# before rename().
+#
# Define WITH_OWN_SUBPROCESS_PY if you want to use with python 2.3.
#
# Define NO_IPV6 if you lack IPv6 support and getaddrinfo().

@@ -270,6 +273,8 @@

# NO_MMAP = YesPlease
NO_IPV6 = YesPlease
X = .exe
+ MUMNAP_BEFORE_RENAME = YesPlease
+ NO_SOCKADDR_STORAGE = YesPlease
endif
ifeq ($(uname_S),FreeBSD)
NEEDS_LIBICONV = YesPlease

--- cache.h.000 2006-05-02 11:35:50.000000000 +0300
+++ cache.h 2006-05-02 11:33:34.000000000 +0300

@@ -140,6 +140,7 @@

/* Initialize and use the cache information */
extern int read_cache(void);
+extern void unmap_cache(void);
extern int write_cache(int newfd, struct cache_entry **cache, int entries);
extern int cache_name_pos(const char *name, int namelen);
#define ADD_CACHE_OK_TO_ADD 1 /* Ok to add */

--- read-cache.c.000 2006-05-07 22:33:42.000000000 +0300
+++ read-cache.c 2006-05-02 11:32:56.000000000 +0300

@@ -513,6 +513,9 @@

return 0;
}

+static void *mapaddr = MAP_FAILED;
+static unsigned long mapsize;
+
int read_cache(void)
{
int fd, i;

@@ -541,6 +544,8 @@

errno = EINVAL;
if (size >= sizeof(struct cache_header) + 20)
map = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+ mapaddr = map;
+ mapsize = size;
}
close(fd);
if (map == MAP_FAILED)

@@ -565,10 +570,19 @@

unmap:
munmap(map, size);
+ mapaddr = MAP_FAILED;
errno = EINVAL;
die("index file corrupt");
}

+void unmap_cache(void)
+{
+ if ( mapaddr != MAP_FAILED ) {
+ munmap(mapaddr, mapsize);
+ mapaddr = MAP_FAILED;
+ }
+}
+
#define WRITE_BUFFER_SIZE 8192
static unsigned char write_buffer[WRITE_BUFFER_SIZE];
static unsigned long write_buffer_len;

--- index.c.000 2006-05-07 22:36:04.000000000 +0300
+++ index.c 2006-05-07 22:36:40.000000000 +0300

@@ -43,6 +43,9 @@

strcpy(indexfile, cf->lockfile);
i = strlen(indexfile) - 5; /* .lock */
indexfile[i] = 0;
+#ifdef MUMNAP_BEFORE_RENAME
+ unmap_cache();
+#endif
i = rename(cf->lockfile, indexfile);
cf->lockfile[0] = 0;
return i;