Re: [Bug-tar] oldgnu file format changes (file permissions field).

[Sergey Poznyakoff]

Igor Zhbanov <address@hidden> ha escrit:

> Hello!

Hi,

> I have found that tar´s after 1.16 creates binary different archives
> in oldgnu format.
> The difference is in file mode field.

Thanks. Please try the attached patch.

Regards,
Sergey

diff --git a/src/common.h b/src/common.h
index 73865ec..1a6ca8b 100644
--- a/src/common.h
+++ b/src/common.h
@@ -557,7 +557,8 @@ char const *tartime (struct timespec t, bool full_time);
 #define GID_FROM_HEADER(where) gid_from_header (where, sizeof (where))
 #define MAJOR_FROM_HEADER(where) major_from_header (where, sizeof (where))
 #define MINOR_FROM_HEADER(where) minor_from_header (where, sizeof (where))
-#define MODE_FROM_HEADER(where) mode_from_header (where, sizeof (where))
+#define MODE_FROM_HEADER(where, hbits) \
+  mode_from_header (where, sizeof (where), hbits)
 #define OFF_FROM_HEADER(where) off_from_header (where, sizeof (where))
 #define SIZE_FROM_HEADER(where) size_from_header (where, sizeof (where))
 #define TIME_FROM_HEADER(where) time_from_header (where, sizeof (where))
@@ -567,7 +568,7 @@ char const *tartime (struct timespec t, bool full_time);
 gid_t gid_from_header (const char *buf, size_t size);
 major_t major_from_header (const char *buf, size_t size);
 minor_t minor_from_header (const char *buf, size_t size);
-mode_t mode_from_header (const char *buf, size_t size);
+mode_t mode_from_header (const char *buf, size_t size, unsigned *hbits);
 off_t off_from_header (const char *buf, size_t size);
 size_t size_from_header (const char *buf, size_t size);
 time_t time_from_header (const char *buf, size_t size);
diff --git a/src/create.c b/src/create.c
index 6f3113e..79c80ce 100644
--- a/src/create.c
+++ b/src/create.c
@@ -402,8 +402,7 @@ mode_to_chars (mode_t v, char *p, size_t s)
       && S_IROTH == TOREAD && S_IWOTH == TOWRITE && S_IXOTH == TOEXEC
       && archive_format != POSIX_FORMAT
       && archive_format != USTAR_FORMAT
-      && archive_format != GNU_FORMAT
-      && archive_format != OLDGNU_FORMAT)
+      && archive_format != GNU_FORMAT)
     {
       negative = v < 0;
       u = v;
diff --git a/src/list.c b/src/list.c
index 2436901..bba430a 100644
--- a/src/list.c
+++ b/src/list.c
@@ -531,7 +531,9 @@ decode_header (union block *header, struct tar_stat_info 
*stat_info,
               enum archive_format *format_pointer, int do_user_group)
 {
   enum archive_format format;
-
+  unsigned hbits; /* high bits of the file mode. */
+  mode_t mode = MODE_FROM_HEADER (header->header.mode, &hbits);
+  
   if (strcmp (header->header.magic, TMAGIC) == 0)
     {
       if (header->star_header.prefix[130] == 0
@@ -546,12 +548,12 @@ decode_header (union block *header, struct tar_stat_info 
*stat_info,
        format = USTAR_FORMAT;
     }
   else if (strcmp (header->header.magic, OLDGNU_MAGIC) == 0)
-    format = OLDGNU_FORMAT;
+    format = hbits ? OLDGNU_FORMAT : GNU_FORMAT;
   else
     format = V7_FORMAT;
   *format_pointer = format;
 
-  stat_info->stat.st_mode = MODE_FROM_HEADER (header->header.mode);
+  stat_info->stat.st_mode = mode;
   stat_info->mtime.tv_sec = TIME_FROM_HEADER (header->header.mtime);
   stat_info->mtime.tv_nsec = 0;
   assign_string (&stat_info->uname,
@@ -885,25 +887,28 @@ minor_from_header (const char *p, size_t s)
                      (uintmax_t) TYPE_MAXIMUM (minor_t), false, false);
 }
 
+/* Convert P to the file mode, as understood by tar.
+   Store unrecognized mode bits (from 10th up) in HBITS. */
 mode_t
-mode_from_header (const char *p, size_t s)
+mode_from_header (const char *p, size_t s, unsigned *hbits)
 {
-  /* Do not complain about unrecognized mode bits.  */
   unsigned u = from_header (p, s, "mode_t",
                            - (uintmax_t) TYPE_MINIMUM (mode_t),
                            TYPE_MAXIMUM (uintmax_t), false, false);
-  return ((u & TSUID ? S_ISUID : 0)
-         | (u & TSGID ? S_ISGID : 0)
-         | (u & TSVTX ? S_ISVTX : 0)
-         | (u & TUREAD ? S_IRUSR : 0)
-         | (u & TUWRITE ? S_IWUSR : 0)
-         | (u & TUEXEC ? S_IXUSR : 0)
-         | (u & TGREAD ? S_IRGRP : 0)
-         | (u & TGWRITE ? S_IWGRP : 0)
-         | (u & TGEXEC ? S_IXGRP : 0)
-         | (u & TOREAD ? S_IROTH : 0)
-         | (u & TOWRITE ? S_IWOTH : 0)
-         | (u & TOEXEC ? S_IXOTH : 0));
+  mode_t mode = ((u & TSUID ? S_ISUID : 0)
+                | (u & TSGID ? S_ISGID : 0)
+                | (u & TSVTX ? S_ISVTX : 0)
+                | (u & TUREAD ? S_IRUSR : 0)
+                | (u & TUWRITE ? S_IWUSR : 0)
+                | (u & TUEXEC ? S_IXUSR : 0)
+                | (u & TGREAD ? S_IRGRP : 0)
+                | (u & TGWRITE ? S_IWGRP : 0)
+                | (u & TGEXEC ? S_IXGRP : 0)
+                | (u & TOREAD ? S_IROTH : 0)
+                | (u & TOWRITE ? S_IWOTH : 0)
+                | (u & TOEXEC ? S_IXOTH : 0));
+  *hbits = mode ^ u;
+  return mode;
 }
 
 off_t