t/lib-chunk.sh

   1 # Shell library for working with "chunk" files (commit-graph, midx, etc).
   2
   3 # corrupt_chunk_file <fn> <chunk> <offset> <bytes>
   4 #
   5 # Corrupt a chunk-based file (like a commit-graph) by overwriting the bytes
   6 # found in the chunk specified by the 4-byte <chunk> identifier. If <offset> is
   7 # "clear", replace the chunk entirely. Otherwise, overwrite data <offset> bytes
   8 # into the chunk.
   9 #
  10 # The <bytes> are interpreted as pairs of hex digits (so "000000FE" would be
  11 # big-endian 254).
  12 corrupt_chunk_file () {
  13         fn=$1; shift
  14         perl "$TEST_DIRECTORY"/lib-chunk/corrupt-chunk-file.pl \
  15                 "$@" <"$fn" >"$fn.tmp" &&
  16         # some vintages of macOS 'mv' fails to overwrite a read-only file.
  17         mv -f "$fn.tmp" "$fn"
  18 }