build: new configure option --enable-gcc-warnings

[chaz/tar] / src / sparse.c

diff --git a/src/sparse.c b/src/sparse.c
index 8af4b47b8da1920cbabe6f0792339c5acdb49409..f7a9fe7c93ff046b12f19054fde10d787e097c14 100644 (file)
--- a/src/sparse.c
+++ b/src/sparse.c
@@ -217,43 +217,45 @@ sparse_scan_file (struct tar_sparse_file *file)
   struct tar_stat_info *st = file->stat_info;
   int fd = file->fd;
   char buffer[BLOCKSIZE];
-  size_t count;
+  size_t count = 0;
   off_t offset = 0;
   struct sp_array sp = {0, 0};
 
-  if (!lseek_or_error (file, 0))
-    return false;
-
   st->archive_file_size = 0;
 
-  if (!tar_sparse_scan (file, scan_begin, NULL))
-    return false;
-
-  while ((count = safe_read (fd, buffer, sizeof buffer)) != 0
-        && count != SAFE_READ_ERROR)
+  if (ST_NBLOCKS (st->stat) == 0)
+    offset = st->stat.st_size;
+  else
     {
-      /* Analyze the block.  */
-      if (zero_block_p (buffer, count))
+      if (!tar_sparse_scan (file, scan_begin, NULL))
+       return false;
+
+      while ((count = blocking_read (fd, buffer, sizeof buffer)) != 0
+            && count != SAFE_READ_ERROR)
        {
-         if (sp.numbytes)
+         /* Analyze the block.  */
+         if (zero_block_p (buffer, count))
            {
-             sparse_add_map (st, &sp);
-             sp.numbytes = 0;
-             if (!tar_sparse_scan (file, scan_block, NULL))
+             if (sp.numbytes)
+               {
+                 sparse_add_map (st, &sp);
+                 sp.numbytes = 0;
+                 if (!tar_sparse_scan (file, scan_block, NULL))
+                   return false;
+               }
+           }
+         else
+           {
+             if (sp.numbytes == 0)
+               sp.offset = offset;
+             sp.numbytes += count;
+             st->archive_file_size += count;
+             if (!tar_sparse_scan (file, scan_block, buffer))
                return false;
            }
-       }
-      else
-       {
-         if (sp.numbytes == 0)
-           sp.offset = offset;
-         sp.numbytes += count;
-         st->archive_file_size += count;
-         if (!tar_sparse_scan (file, scan_block, buffer))
-           return false;
-       }
 
-      offset += count;
+         offset += count;
+       }
     }
 
   if (sp.numbytes == 0)
@@ -358,7 +360,7 @@ sparse_extract_region (struct tar_sparse_file *file, size_t i)
          return false;
        }
       set_next_block_after (blk);
-      count = full_write (file->fd, blk->buffer, wrbytes);
+      count = blocking_write (file->fd, blk->buffer, wrbytes);
       write_size -= count;
       file->dumped_size += count;
       mv_size_left (file->stat_info->archive_file_size - file->dumped_size);
@@ -589,18 +591,18 @@ sparse_diff_file (int fd, struct tar_stat_info *st)
 /* Old GNU Format. The sparse file information is stored in the
    oldgnu_header in the following manner:
 
-   The header is marked with type 'S'. Its `size' field contains
+   The header is marked with type 'S'. Its 'size' field contains
    the cumulative size of all non-empty blocks of the file. The
-   actual file size is stored in `realsize' member of oldgnu_header.
+   actual file size is stored in 'realsize' member of oldgnu_header.
 
-   The map of the file is stored in a list of `struct sparse'.
+   The map of the file is stored in a list of 'struct sparse'.
    Each struct contains offset to the block of data and its
    size (both as octal numbers). The first file header contains
    at most 4 such structs (SPARSES_IN_OLDGNU_HEADER). If the map
-   contains more structs, then the field `isextended' of the main
-   header is set to 1 (binary) and the `struct sparse_header'
+   contains more structs, then the field 'isextended' of the main
+   header is set to 1 (binary) and the 'struct sparse_header'
    header follows, containing at most 21 following structs
-   (SPARSES_IN_SPARSE_HEADER). If more structs follow, `isextended'
+   (SPARSES_IN_SPARSE_HEADER). If more structs follow, 'isextended'
    field of the extended header is set and next  next extension header
    follows, etc... */
 
@@ -1027,8 +1029,11 @@ pax_dump_header_1 (struct tar_sparse_file *file)
   xheader_store ("GNU.sparse.name", file->stat_info, NULL);
   xheader_store ("GNU.sparse.realsize", file->stat_info, NULL);
 
-  file->stat_info->file_name = xheader_format_name (file->stat_info,
-                                           "%d/GNUSparseFile.%p/%f", 0);
+  file->stat_info->file_name =
+    xheader_format_name (file->stat_info, "%d/GNUSparseFile.%p/%f", 0);
+  /* Make sure the created header name is shorter than NAME_FIELD_SIZE: */
+  if (strlen (file->stat_info->file_name) > NAME_FIELD_SIZE)
+    file->stat_info->file_name[NAME_FIELD_SIZE] = 0;
 
   blk = start_header (file->stat_info);
   /* Store the effective (shrunken) file size */