pentaho/pentaho-kettle · error · RhinoRuntimeError

start smaller than 0

Error message

start smaller than 0

What it means

Domain guard in substr's 3-argument branch: the start position computed from ArgList[1] is negative, which String.substring rejects. The check fires before length clamping (negative lengths are silently treated as 0 for JS compatibility, but negative starts are not).

Solutions

1. Use a zero-based non-negative start index
2. Clamp the start in script: Math.max(0, start)

When it happens

Trigger: Thrown at engine/src/main/java/org/pentaho/di/trans/steps/scriptvalues_mod/ScriptValuesAddedFunctions.java:1687 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/aca667e7b1107399. Report an issue: GitHub.

Appendix: source

Thrown at engine/src/main/java/org/pentaho/di/trans/steps/scriptvalues_mod/ScriptValuesAddedFunctions.java:1687

      } catch ( Exception e ) {
        throw Context.reportRuntimeError( "The function call substr is not valid : " + e.getMessage() );
      }
    } else if ( ArgList.length == 3 ) {
      try {
        int to;
        int strLen;

        if ( isNull( ArgList[0] ) ) {
          return null;
        } else if ( isUndefined( ArgList[0] ) ) {
          return (String) Context.getUndefinedValue();
        }
        sRC = Context.toString( ArgList[0] );
        int from = (int) Math.round( Context.toNumber( ArgList[1] ) );
        int len = (int) Math.round( Context.toNumber( ArgList[2] ) );

        if ( from < 0 ) {
          throw Context.reportRuntimeError( "start smaller than 0" );
        }
        if ( len < 0 ) {
          len = 0; // Make it compatible with Javascript substr
        }

        to = from + len;
        strLen = sRC.length();
        if ( to > strLen ) {
          to = strLen;
        }
        sRC = sRC.substring( from, to );
      } catch ( Exception e ) {
        throw Context.reportRuntimeError( "The function call substr is not valid : " + e.getMessage() );
      }
    } else {
      throw Context.reportRuntimeError( "The function call substr requires 2 or 3 arguments." );
    }
    return sRC;

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