GNU Bash bugs

This is a list of the bugs in GNU Bash that I’ve reported:

• Improper array name validation for the ‘mapfile’ builtin

• Segmentation fault when running recursive traps

• Issue when using job control and SIGCHLD with bash 4.3 (trap is not being run)

• Bash does not follow POSIX when return is called during the action of a trap

• Executing ‘return’ inside RETURN trap causes function to recurse infinitely

  f(){ trap return RETURN; }; f

• Parent shell gets stopped when a child shell is created with job control but not interactive (bash -mc)

  bash -s <<< 'for i in . .; do (bash -mc ": & wait") ; done'

• Invalid byte sequence under UTF-8 locale generates a segmentation fault when using printf %q (ansic_quote)

  $ cat command-name 
  payload=$'\065\247\100\063\231\053\306\123\070\237\242\352\263'
  "$payload"
    
  $ cat printf-q 
  payload=$'\065\247\100\063\231\053\306\123\070\237\242\352\263'
  printf %q "$payload"
    
  $ cat set-x 
  payload=$'\065\247\100\063\231\053\306\123\070\237\242\352\263'
  (set -x; : "$payload")
  

• DEL character treated specially when preceded by a backslash when used in the RHS of the regex operator ([[ $'\177' =~ $'\\\177' ]])

  for c in $'\001' $'\a' $'\177' $'\377'; do
      for r in "$c" "\\$c" "\\[$c]"; do
          [[ $c =~ $r ]];
          printf '[[ %q =~ %q ]] -> %d\n' "$c" "$r" "$?";
      done; printf %s\\n ---;
  done;
  

• Unexpected behavior of single quotes when used in the patsub PE

  #!/usr/bin/env bash
  for shell in bash mksh ksh zsh; do
  "$shell" <<'EOF'
    t() {
      printf '%s  |  %s\n' "$1" "$2"
    }
    v="'"       # v <- '
    
    printf '===\n%s %s\n---\n' \
      "$0" \
      "$BASH_VERSION"
    
    #--
    t "${v/$'\''/$'\''}"        "'"
    t  ${v/$'\''/$'\''}         "'"
    t "${v/$'\''/x}"            "x"
    t  ${v/$'\''/x}             "x"
    t "${v/x/$'\''}"            "'"
    t  ${v/x/$'\''}             "'"
    t "${v/x/$'\x5c\''}"        "'" #< I would actually expect these to
    t  ${v/x/$'\x5c\''}         "'" #< be \'
    t "${v/\'/\'}"              "'"
    t  ${v/\'/\'}               "'"
  EOF
  done
  

• Behaviour of brace expansion is different in devel branch

  echo x{,}

• Segmentation fault in arithmetical expression when mixing array variables

   #!/bin/bash
     
   echo "$BASH_VERSION"
   echo $(( a=(y[0] + y[1]) & 0xff, b=(y[2] + y[3]) & 0xff, a << 8 | b))
     
   # simpler
   ( y=(1 2); (( _ = y[0], _ = 1 )) ) # crash
  

• %(fmt)T fails with large times in 64-bit linux

   for i in {56..63}; do
       printf '%s ' $i;
       bash -c 'printf %\(%s\)T\\n $((2**$1))' _ $i;
   done