[IMPALA-8497] SQL return ArrayIndexOutOfBoundsException when ends with '\n'

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: Impala 3.2.0
• Fix Version/s: Impala 3.3.0
• Component/s: Frontend
• Epic Color: ghx-label-6
• Assignee: Sheng Wang
• Reporter: Sheng Wang
• Created: 06/May/19 12:13
• Updated: 20/May/19 15:50
• Resolved: 20/May/19 15:50

Description

When submit sql with jdbc in code, those sqls return "ArrayIndexOutOfBoundsException" instead of "Syntax error":

show\n
select\n

This is mainly caused by code below:

//sql-parser.cup
  public String getErrorMsg(String stmt) {
    if (errorToken_ == null || stmt == null) return null;
    String[] lines = stmt.split("\n");
    StringBuffer result = new StringBuffer();
    result.append(getErrorTypeMessage(errorToken_.sym) + " in line ");
    result.append(errorToken_.left);
    result.append(":\n");

    // errorToken_.left is the line number of error.
    // errorToken_.right is the column number of the error.
    String errorLine = lines[errorToken_.left - 1];
    //......

because these sqls are ends with '\n', the length of 'lines' array is small than 'errorToken_.left - 1', and thus throw ArrayIndexOutOfBoundsException, and this exception cannot be catched.