Document --unified/-U option

diff --git a/compat/mmap.c b/compat/mmap.c
index bb34c7e95f6aafd6b8a433db0b2ceb0a68086817..c9d46d174259f42a3e2a2eb073475aba517044be 100644 (file)
--- a/compat/mmap.c
+++ b/compat/mmap.c
@@ -2,17 +2,11 @@
 
 void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
 {
-       int n = 0;
-       off_t current_offset = lseek(fd, 0, SEEK_CUR);
+       size_t n = 0;
 
        if (start != NULL || !(flags & MAP_PRIVATE))
                die("Invalid usage of mmap when built with NO_MMAP");
 
-       if (lseek(fd, offset, SEEK_SET) < 0) {
-               errno = EINVAL;
-               return MAP_FAILED;
-       }
-
        start = xmalloc(length);
        if (start == NULL) {
                errno = ENOMEM;
@@ -20,14 +14,16 @@ void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t of
        }
 
        while (n < length) {
-               int count = read(fd, start+n, length-n);
+               ssize_t count = pread(fd, (char *)start + n, length - n, offset + n);
 
                if (count == 0) {
-                       memset(start+n, 0, length-n);
+                       memset((char *)start+n, 0, length-n);
                        break;
                }
 
                if (count < 0) {
+                       if (errno == EAGAIN || errno == EINTR)
+                               continue;
                        free(start);
                        errno = EACCES;
                        return MAP_FAILED;
@@ -36,11 +32,6 @@ void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t of
                n += count;
        }
 
-       if (current_offset != lseek(fd, current_offset, SEEK_SET)) {
-               errno = EINVAL;
-               return MAP_FAILED;
-       }
-
        return start;
 }
 
@@ -49,4 +40,3 @@ int git_munmap(void *start, size_t length)
        free(start);
        return 0;
 }
-