Make xhdr_tab extern, not static.

[chaz/tar] / src / xheader.c

diff --git a/src/xheader.c b/src/xheader.c
index 6f8c140b12cdd229b8551ca26a4386893f906534..1441eec8728b5e14f4d1f5bdcf74737fcea20586 100644 (file)
--- a/src/xheader.c
+++ b/src/xheader.c
@@ -18,9 +18,7 @@
 
 #include "system.h"
 
-#include <grp.h>
 #include <hash.h>
-#include <pwd.h>
 #include <quotearg.h>
 
 #include "common.h"
@@ -38,7 +36,13 @@ struct xhdr_tab
   void (*decoder) (struct tar_stat_info *, char const *);
 };
 
-static struct xhdr_tab const xhdr_tab[];
+/* This declaration must be extern, because ISO C99 section 6.9.2
+   prohibits a tentative definition that has both internal linkage and
+   incomplete type.  If we made it static, we'd have to declare its
+   size which would be a maintenance pain; if we put its initializer
+   here, we'd need a boatload of forward declarations, which would be
+   even more of a pain.  */
+extern struct xhdr_tab const xhdr_tab[];
 
 static struct xhdr_tab const *
 locate_handler (char const *keyword)
@@ -51,6 +55,9 @@ locate_handler (char const *keyword)
   return NULL;
 }
 
+/* Decodes a single extended header record. Advances P to the next
+   record.
+   Returns true on success, false otherwise. */
 static bool
 decode_record (char **p, struct tar_stat_info *st)
 {
@@ -61,13 +68,13 @@ decode_record (char **p, struct tar_stat_info *st)
   struct xhdr_tab const *t;
 
   if (**p == 0)
-    return true;
+    return false;
 
   len = strtoul (*p, p, 10);
   if (**p != ' ')
     {
-      ERROR ((0, 0, _("Malformed extended header")));
-      return true;
+      ERROR ((0, 0, _("Malformed extended header: missing whitespace after the length")));
+      return false;
     }
 
   keyword = ++*p;
@@ -77,8 +84,8 @@ decode_record (char **p, struct tar_stat_info *st)
 
   if (**p != '=')
     {
-      ERROR ((0, 0, _("Malformed extended header")));
-      return true;
+      ERROR ((0, 0, _("Malformed extended header: missing equal sign")));
+      return false;
     }
 
   eqp = *p;
@@ -98,17 +105,17 @@ decode_record (char **p, struct tar_stat_info *st)
     }
   *eqp = '=';
   *p = &start[len];
-  return false;
+  return true;
 }
 
 void
 xheader_decode (struct tar_stat_info *st)
 {
-  char *p = extended_header.buffer;
+  char *p = extended_header.buffer + BLOCKSIZE;
   char *endp = &extended_header.buffer[extended_header.size-1];
 
   while (p < endp)
-    if (decode_record (&p, st))
+    if (!decode_record (&p, st))
       break;
 }
 
@@ -133,29 +140,31 @@ xheader_store (char const *keyword, struct tar_stat_info const *st)
 void
 xheader_read (union block *p, size_t size)
 {
-  size_t i, j;
+  size_t j = 0;
   size_t nblocks;
 
   free (extended_header.buffer);
+  size += BLOCKSIZE;
   extended_header.size = size;
   nblocks = (size + BLOCKSIZE - 1) / BLOCKSIZE;
   extended_header.buffer = xmalloc (size + 1);
 
-  set_next_block_after (p);
-  for (i = j = 0; i < nblocks; i++)
+  do
     {
-      size_t len;
+      size_t len = size;
 
-      p = find_next_block ();
-      len = size;
       if (len > BLOCKSIZE)
        len = BLOCKSIZE;
+      
       memcpy (&extended_header.buffer[j], p->buffer, len);
       set_next_block_after (p);
 
+      p = find_next_block ();
+
       j += len;
       size -= len;
     }
+  while (size > 0);
 }
 
 static size_t
@@ -403,7 +412,7 @@ uname_decoder (struct tar_stat_info *st, char const *arg)
   assign_string (&st->uname, arg);
 }
 
-static struct xhdr_tab const xhdr_tab[] = {
+struct xhdr_tab const xhdr_tab[] = {
   { "atime",   atime_coder,    atime_decoder   },
   { "comment", dummy_coder,    dummy_decoder   },
   { "charset", dummy_coder,    dummy_decoder   },
@@ -417,6 +426,9 @@ static struct xhdr_tab const xhdr_tab[] = {
   { "uid",     uid_coder,      uid_decoder     },
   { "uname",   uname_coder,    uname_decoder   },
 
+  /* The number of entries in xhdr_tab must agree with the array
+     bounds in xhdr_tab's forward declaration.  */
+
 #if 0 /* GNU private keywords (not yet implemented) */
   /* Sparse file handling */
   { "GNU.sparse.offset",     sparse_offset_coder, sparse_offset_decoder },