Re: [Bug-tar] tar 1.16 segmentation fault

[Sergey Poznyakoff]

Karl Berry <address@hidden> wrote:

> I typed (by mistake):
> tar czfT x.tgz `cat /tmp/b`
> 
> and got:
> Segmentation fault

Thank you. I have installed the following fix:

2006-11-01  Sergey Poznyakoff  <address@hidden>

        * src/tar.c: Handle zero-length entries in a files-from file
        
Index: src/tar.c
===================================================================
RCS file: /cvsroot/tar/tar/src/tar.c,v
retrieving revision 1.160
diff -p -u -r1.160 tar.c
--- src/tar.c   17 Oct 2006 08:13:43 -0000      1.160
+++ src/tar.c   1 Nov 2006 00:15:40 -0000
@@ -953,7 +953,8 @@ enum read_file_list_state  /* Result of 
   {
     file_list_success,     /* OK, name read successfully */
     file_list_end,         /* End of list file */
-    file_list_zero         /* Zero separator encountered where it should not */
+    file_list_zero,        /* Zero separator encountered where it should not */
+    file_list_skip         /* Empty (zero-length) entry encountered, skip it */
   };
 
 /* Read from FP a sequence of characters up to FILENAME_TERMINATOR and put them
@@ -971,13 +972,15 @@ read_name_from_file (FILE *fp, struct ob
        {
          /* We have read a zero separator. The file possibly is
             zero-separated */
-         /* FATAL_ERROR((0, 0, N_("file name contains null character"))); */
          return file_list_zero;
        }
       obstack_1grow (stk, c);
       counter++;
     }
 
+  if (counter == 0 && c != EOF)
+    return file_list_skip;
+  
   obstack_1grow (stk, 0);
 
   return (counter == 0 && c == EOF) ? file_list_end : file_list_success;
@@ -1058,31 +1061,42 @@ update_argv (const char *filename, struc
        open_fatal (filename);
     }
 
-  while ((read_state = read_name_from_file (fp, &argv_stk)) == 
file_list_success)
-    count++;
-
-  if (read_state == file_list_zero)
+  while ((read_state = read_name_from_file (fp, &argv_stk)) != file_list_end)
     {
-      size_t size;
+      switch (read_state)
+       {
+       case file_list_success:
+         count++;
+         break;
+         
+       case file_list_end: /* won't happen, just to pacify gcc */
+         break;
 
-      WARN ((0, 0, N_("%s: file name read contains nul character"),
-            quotearg_colon (filename)));
+       case file_list_zero:
+         {
+           size_t size;
 
-      /* Prepare new stack contents */
-      size = obstack_object_size (&argv_stk);
-      p = obstack_finish (&argv_stk);
-      for (; size > 0; size--, p++)
-       if (*p)
-         obstack_1grow (&argv_stk, *p);
-        else
-         obstack_1grow (&argv_stk, '\n');
-      obstack_1grow (&argv_stk, 0);
-      count = 1;
-
-      /* Read rest of files using new filename terminator */
-      filename_terminator = 0;
-      while (read_name_from_file (fp, &argv_stk) == file_list_success)
-       count++;
+           WARN ((0, 0, N_("%s: file name read contains nul character"),
+                  quotearg_colon (filename)));
+
+           /* Prepare new stack contents */
+           size = obstack_object_size (&argv_stk);
+           p = obstack_finish (&argv_stk);
+           for (; size > 0; size--, p++)
+             if (*p)
+               obstack_1grow (&argv_stk, *p);
+             else
+               obstack_1grow (&argv_stk, '\n');
+           obstack_1grow (&argv_stk, 0);
+           count = 1;
+           /* Read rest of files using new filename terminator */
+           filename_terminator = 0;
+           break;
+         }
+         
+       case file_list_skip:
+         break;
+       }
     }
 
   if (!is_stdin)


Regards,
Sergey