Variable assignments before an `if` statement may prevent it from being parsed correctly

[dmitmel]

Suppose we have the following minimal example:

handle_mime() {
  mime="$1" uncompressed_filename="$2"

  if [ -z "$decompress" ]; then
    case "$mime" in
    esac
  fi
}

It gets parsed as:

(program ; [0, 0] - [8, 0]
  (function_definition ; [0, 0] - [7, 1]
    name: (word) ; [0, 0] - [0, 11]
    body: (compound_statement ; [0, 14] - [7, 1]
      (command ; [1, 2] - [3, 25]
        (variable_assignment ; [1, 2] - [1, 11]
          name: (variable_name) ; [1, 2] - [1, 6]
          value: (string ; [1, 7] - [1, 11]
            (simple_expansion ; [1, 8] - [1, 10]
              (variable_name)))) ; [1, 9] - [1, 10]
        (variable_assignment ; [1, 12] - [1, 38]
          name: (variable_name) ; [1, 12] - [1, 33]
          value: (string ; [1, 34] - [1, 38]
            (simple_expansion ; [1, 35] - [1, 37]
              (variable_name)))) ; [1, 36] - [1, 37]
        name: (command_name ; [3, 2] - [3, 4]
          (word)) ; [3, 2] - [3, 4]
        argument: (word) ; [3, 5] - [3, 6]
        argument: (word) ; [3, 7] - [3, 9]
        argument: (string ; [3, 10] - [3, 23]
          (simple_expansion ; [3, 11] - [3, 22]
            (variable_name))) ; [3, 12] - [3, 22]
        argument: (word)) ; [3, 24] - [3, 25]
      (command ; [3, 27] - [3, 31]
        name: (command_name ; [3, 27] - [3, 31]
          (word))) ; [3, 27] - [3, 31]
      (case_statement ; [4, 4] - [5, 8]
        value: (string ; [4, 9] - [4, 16]
          (simple_expansion ; [4, 10] - [4, 15]
            (variable_name)))) ; [4, 11] - [4, 15]
      (command ; [6, 2] - [6, 4]
        name: (command_name ; [6, 2] - [6, 4]
          (word)))))) ; [6, 2] - [6, 4]

Notice the lack of an if_statement node. If I add a semicolon after the variable assignments on the second line, it becomes correctly parsed as:

(program ; [0, 0] - [8, 0]
  (function_definition ; [0, 0] - [7, 1]
    name: (word) ; [0, 0] - [0, 11]
    body: (compound_statement ; [0, 14] - [7, 1]
      (variable_assignments ; [1, 2] - [1, 38]
        (variable_assignment ; [1, 2] - [1, 11]
          name: (variable_name) ; [1, 2] - [1, 6]
          value: (string ; [1, 7] - [1, 11]
            (simple_expansion ; [1, 8] - [1, 10]
              (variable_name)))) ; [1, 9] - [1, 10]
        (variable_assignment ; [1, 12] - [1, 38]
          name: (variable_name) ; [1, 12] - [1, 33]
          value: (string ; [1, 34] - [1, 38]
            (simple_expansion ; [1, 35] - [1, 37]
              (variable_name))))) ; [1, 36] - [1, 37]
      (if_statement ; [3, 2] - [6, 4]
        condition: (test_command ; [3, 5] - [3, 25]
          (unary_expression ; [3, 7] - [3, 23]
            operator: (test_operator) ; [3, 7] - [3, 9]
            (string ; [3, 10] - [3, 23]
              (simple_expansion ; [3, 11] - [3, 22]
                (variable_name))))) ; [3, 12] - [3, 22]
        (case_statement ; [4, 4] - [5, 8]
          value: (string ; [4, 9] - [4, 16]
            (simple_expansion ; [4, 10] - [4, 15]
              (variable_name)))))))) ; [4, 11] - [4, 15]

The difference is, without a semicolon, all this text is mushed into a single command node:

  mime="$1" uncompressed_filename="$2"

  if [ -z "$decompress" ]