(to_chars): Generate GNU base-64 representation if we are generating

[chaz/tar] / src / create.c

diff --git a/src/create.c b/src/create.c
index 81066b4dcfac4805e4147a8fafcac814ddc283e4..42c82fffe71d2a7b9716cf42ca6e31f7506f965f 100644 (file)
--- a/src/create.c
+++ b/src/create.c
@@ -114,25 +114,38 @@ to_chars (int negative, uintmax_t value, size_t valsize,
 {
   uintmax_t v = negative ? -value : value;
 
+  /* Generate the POSIX octal representation if the number fits.  */
   if (! negative && v <= MAX_VAL_WITH_DIGITS (size - 1, LG_8))
     {
       where[size - 1] = '\0';
       to_base (v, LG_8, base_8_digits, where, size - 1);
     }
+
+  /* Otherwise, generate the GNU base-64 representation if we are
+     generating an old or new GNU format and if the number fits.  */
   else if (v <= MAX_VAL_WITH_DIGITS (size - 1, LG_64)
-          && archive_format == GNU_FORMAT)
+          && (archive_format == GNU_FORMAT
+              || archive_format == OLDGNU_FORMAT))
     {
       where[0] = negative ? '-' : '+';
       to_base (v, LG_64, base_64_digits, where + 1, size - 1);
     }
-  else if (negative
-          && archive_format != GNU_FORMAT
-          && valsize * CHAR_BIT <= (size - 1) * LG_8)
+
+  /* Otherwise, if the number is negative, and if it would not cause
+     ambiguity on this host by confusing positive with negative
+     values, then generate the POSIX octal representation of the value
+     modulo 2**(field bits).  The resulting tar file is
+     machine-dependent, since it depends on the host word size.  Yuck!
+     But this is the traditional behavior.  */
+  else if (negative && valsize * CHAR_BIT <= (size - 1) * LG_8)
     {
       where[size - 1] = '\0';
       to_base (value & MAX_VAL_WITH_DIGITS (valsize * CHAR_BIT, 1),
               LG_8, base_8_digits, where, size - 1);
     }
+
+  /* Otherwise, output a substitute value if possible (with a
+     warning), and an error message if not.  */
   else
     {
       uintmax_t maxval = (archive_format == GNU_FORMAT
@@ -298,7 +311,7 @@ clear_buffer (char *buffer)
 }
 
 /*-------------------------------------------------------------------------.
-| Write the EOT block(s).  We actually zero at least one block, through           |
+| Write the EOT block(s).  We zero at least two blocks, through                   |
 | the end of the record.  Old tar, as previous versions of GNU tar, writes |
 | garbage after two zeroed blocks.                                        |
 `-------------------------------------------------------------------------*/
@@ -307,14 +320,11 @@ void
 write_eot (void)
 {
   union block *pointer = find_next_block ();
-
-  if (pointer)
-    {
-      size_t space = available_space_after (pointer);
-
-      memset (pointer->buffer, 0, space);
-      set_next_block_after (pointer);
-    }
+  memset (pointer->buffer, 0, BLOCKSIZE);
+  set_next_block_after (pointer);
+  pointer = find_next_block ();
+  memset (pointer->buffer, 0, available_space_after (pointer));
+  set_next_block_after (pointer);
 }
 
 /*-----------------------------------------------------.