[tcljava-dev] Patch: exception during 'string is ...'

[Tom P. <tpo...@ny...>]

This patch fixes an exception thrown during 'string is ...', when 
a zero length value is compared.  E.g.

    % string is integer ""
    Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of range: 0
            at java.lang.String.charAt(String.java:511)
            at tcl.lang.StringCmd.cmdProc(StringCmd.java:458)

With the patch, you get:
    % string is integer ""
    1
    % string is integer -strict ""
    0



This patch is against the 1.3.1 release code.  The patch simply adds an
'else' block at line 359 encompassing the following switch block.

log entry:

* src/jacl/tcl/lang/StringCmd.java: fix StringIndexOutOfBoundsException 
during 'string is' processing when value is zero length.


-- 
Tom Poindexter
tpo...@ny...
http://www.nyx.net/~tpoindex/



--- jacl1.3.1/src/jacl/tcl/lang/StringCmd.java	2003-07-25 02:45:06.000000000 -0600
+++ jacl1.3.1.tp/src/jacl/tcl/lang/StringCmd.java	2003-09-29 15:31:03.000000000 -0600
@@ -355,193 +355,194 @@
 	    if (length1 == 0) {
 		if (strict) {
 		    result = false;
-		}
-	    }
+		} 
+	    } else {
 
-	    switch (index) {
-		case STR_IS_BOOL:
-		case STR_IS_TRUE:
-		case STR_IS_FALSE: {
-		    if (obj.getInternalRep() instanceof TclBoolean) {
-			if (((index == STR_IS_TRUE) &&
-			     !TclBoolean.get(interp, obj)) ||
-			    ((index == STR_IS_FALSE) &&
-			     TclBoolean.get(interp, obj))) {
-			  result = false;
-			}
-		    } else {
-			try {
-			    boolean i = TclBoolean.get(null, obj);
-			    if (((index == STR_IS_TRUE) && !i) ||
-				((index == STR_IS_FALSE) && i)) {
+		switch (index) {
+		    case STR_IS_BOOL:
+		    case STR_IS_TRUE:
+		    case STR_IS_FALSE: {
+			if (obj.getInternalRep() instanceof TclBoolean) {
+			    if (((index == STR_IS_TRUE) &&
+				 !TclBoolean.get(interp, obj)) ||
+				((index == STR_IS_FALSE) &&
+				 TclBoolean.get(interp, obj))) {
 			      result = false;
 			    }
-			} catch (TclException e) {
-			    result = false;
+			} else {
+			    try {
+				boolean i = TclBoolean.get(null, obj);
+				if (((index == STR_IS_TRUE) && !i) ||
+				    ((index == STR_IS_FALSE) && i)) {
+				  result = false;
+				}
+			    } catch (TclException e) {
+				result = false;
+			    }
 			}
-		    }
-		    break;
-		}
-		case STR_IS_DOUBLE: {
-		    if ((obj.getInternalRep() instanceof TclDouble) ||
-			(obj.getInternalRep() instanceof TclInteger)) {
 			break;
 		    }
+		    case STR_IS_DOUBLE: {
+			if ((obj.getInternalRep() instanceof TclDouble) ||
+			    (obj.getInternalRep() instanceof TclInteger)) {
+			    break;
+			}
 
-		    // This is adapted from Tcl_GetDouble
-		    //
-		    // The danger in this function is that
-		    // "12345678901234567890" is an acceptable 'double',
-		    // but will later be interp'd as an int by something
-		    // like [expr].  Therefore, we check to see if it looks
-		    // like an int, and if so we do a range check on it.
-		    // If strtoul gets to the end, we know we either
-		    // received an acceptable int, or over/underflow
+			// This is adapted from Tcl_GetDouble
+			//
+			// The danger in this function is that
+			// "12345678901234567890" is an acceptable 'double',
+			// but will later be interp'd as an int by something
+			// like [expr].  Therefore, we check to see if it looks
+			// like an int, and if so we do a range check on it.
+			// If strtoul gets to the end, we know we either
+			// received an acceptable int, or over/underflow
+
+			if (Expression.looksLikeInt(string1, length1, 0)) {
+			    char c = string1.charAt(0);
+			    int signIx = (c == '-' || c == '+') ? 1 : 0;
+			    StrtoulResult res = Util.strtoul(string1, signIx, 0);
+			    if (res.index == length1) {
+				if (res.errno == TCL.INTEGER_RANGE) {
+				    result = false;
+				    failat = -1;
+				}
+				break;
+			    }
+			}
 
-		    if (Expression.looksLikeInt(string1, length1, 0)) {
 			char c = string1.charAt(0);
 			int signIx = (c == '-' || c == '+') ? 1 : 0;
-			StrtoulResult res = Util.strtoul(string1, signIx, 0);
-			if (res.index == length1) {
-			    if (res.errno == TCL.INTEGER_RANGE) {
-				result = false;
-				failat = -1;
-			    }
-			    break;
-			}
-		    }
+			StrtodResult res = Util.strtod(string1, signIx);
+			if (res.errno == TCL.DOUBLE_RANGE) {
+			    // if (errno == ERANGE), then it was an over/underflow
+			    // problem, but in this method, we only want to know
+			    // yes or no, so bad flow returns 0 (false) and sets
+			    // the failVarObj to the string length.
 
-		    char c = string1.charAt(0);
-		    int signIx = (c == '-' || c == '+') ? 1 : 0;
-		    StrtodResult res = Util.strtod(string1, signIx);
-		    if (res.errno == TCL.DOUBLE_RANGE) {
-			// if (errno == ERANGE), then it was an over/underflow
-			// problem, but in this method, we only want to know
-			// yes or no, so bad flow returns 0 (false) and sets
-			// the failVarObj to the string length.
-
-			result = false;
-			failat = -1;
-		    } else if (res.index == 0) {
-			// In this case, nothing like a number was found
-
-			result = false;
-			failat = 0;
-		    } else {
-			// Go onto SPACE, since we are
-			// allowed trailing whitespace
-
-			failat = res.index;
-			for (int i = res.index; i<length1; i++) {
-			    if (!Character.isWhitespace(string1.charAt(i))) {
-				result = false;
-				break;
+			    result = false;
+			    failat = -1;
+			} else if (res.index == 0) {
+			    // In this case, nothing like a number was found
+
+			    result = false;
+			    failat = 0;
+			} else {
+			    // Go onto SPACE, since we are
+			    // allowed trailing whitespace
+
+			    failat = res.index;
+			    for (int i = res.index; i<length1; i++) {
+				if (!Character.isWhitespace(string1.charAt(i))) {
+				    result = false;
+				    break;
+				}
 			    }
 			}
-		    }
-		    break;
-		}
-		case STR_IS_INT: {
-		    if (obj.getInternalRep() instanceof TclInteger) {
-			break;
-		    }
-		    boolean isInteger = true;
-		    try {
-			TclInteger.get(null, obj);
-		    } catch (TclException e) {
-			isInteger = false;
-		    }
-		    if (isInteger) {
 			break;
 		    }
+		    case STR_IS_INT: {
+			if (obj.getInternalRep() instanceof TclInteger) {
+			    break;
+			}
+			boolean isInteger = true;
+			try {
+			    TclInteger.get(null, obj);
+			} catch (TclException e) {
+			    isInteger = false;
+			}
+			if (isInteger) {
+			    break;
+			}
 
-		    char c = string1.charAt(0);
-		    int signIx = (c == '-' || c == '+') ? 1 : 0;
-		    StrtoulResult res = Util.strtoul(string1, signIx, 0);
-		    if (res.errno == TCL.INTEGER_RANGE) {
-			// if (errno == ERANGE), then it was an over/underflow
-			// problem, but in this method, we only want to know
-			// yes or no, so bad flow returns false and sets
-			// the failVarObj to the string length.
-
-			result = false;
-			failat = -1;
-		    } else if (res.index == 0) {
-			// In this case, nothing like a number was found
-
-			result = false;
-			failat = 0;
-		    } else {
-			// Go onto SPACE, since we are
-			// allowed trailing whitespace
-
-			failat = res.index;
-			for (int i = res.index; i<length1; i++) {
-			    if (!Character.isWhitespace(string1.charAt(i))) {
-				result = false;
-				break;
+			char c = string1.charAt(0);
+			int signIx = (c == '-' || c == '+') ? 1 : 0;
+			StrtoulResult res = Util.strtoul(string1, signIx, 0);
+			if (res.errno == TCL.INTEGER_RANGE) {
+			    // if (errno == ERANGE), then it was an over/underflow
+			    // problem, but in this method, we only want to know
+			    // yes or no, so bad flow returns false and sets
+			    // the failVarObj to the string length.
+
+			    result = false;
+			    failat = -1;
+			} else if (res.index == 0) {
+			    // In this case, nothing like a number was found
+
+			    result = false;
+			    failat = 0;
+			} else {
+			    // Go onto SPACE, since we are
+			    // allowed trailing whitespace
+
+			    failat = res.index;
+			    for (int i = res.index; i<length1; i++) {
+				if (!Character.isWhitespace(string1.charAt(i))) {
+				    result = false;
+				    break;
+				}
 			    }
 			}
+			break;
 		    }
-		    break;
-		}
-		default: {
-		    for (failat = 0; failat < length1; failat++) {
-			char c = string1.charAt(failat);
-			switch (index) {
-			    case STR_IS_ASCII:
-				// This is a valid check in unicode, because
-				// all bytes < 0xC0 are single byte chars
-				// (but isascii limits that def'n to 0x80).
-
-				result = c < 0x80;
-				break;
-			    case STR_IS_ALNUM:
-				result = Character.isLetterOrDigit(c);
-				break;
-			    case STR_IS_ALPHA:
-				result = Character.isLetter(c);
-				break;
-			    case STR_IS_DIGIT:
-				result = Character.isDigit(c);
-				break;
-			    case STR_IS_GRAPH:
-				result = ((1 << Character.getType(c))
-					  & PRINT_BITS) != 0
-					 && c != ' ';
-				break;
-			    case STR_IS_PRINT:
-				result = ((1 << Character.getType(c))
-					  & PRINT_BITS) != 0;
-				break;
-			    case STR_IS_PUNCT:
-				result = ((1 << Character.getType(c))
-					  & PUNCT_BITS) != 0;
-				break;
-			    case STR_IS_UPPER:
-				result = Character.isUpperCase(c);
-				break;
-			    case STR_IS_SPACE:
-				result = Character.isWhitespace(c);
-				break;
-			    case STR_IS_CONTROL:
-				result = Character.isISOControl(c);
-				break;
-			    case STR_IS_LOWER:
-				result = Character.isLowerCase(c);
-				break;
-			    case STR_IS_WORD:
-				result = ((1 << Character.getType(c))
-					  & WORD_BITS) != 0;
-				break;
-			    case STR_IS_XDIGIT:
-				result = Character.digit(c, 16) >= 0;
+		    default: {
+			for (failat = 0; failat < length1; failat++) {
+			    char c = string1.charAt(failat);
+			    switch (index) {
+				case STR_IS_ASCII:
+				    // This is a valid check in unicode, because
+				    // all bytes < 0xC0 are single byte chars
+				    // (but isascii limits that def'n to 0x80).
+
+				    result = c < 0x80;
+				    break;
+				case STR_IS_ALNUM:
+				    result = Character.isLetterOrDigit(c);
+				    break;
+				case STR_IS_ALPHA:
+				    result = Character.isLetter(c);
+				    break;
+				case STR_IS_DIGIT:
+				    result = Character.isDigit(c);
+				    break;
+				case STR_IS_GRAPH:
+				    result = ((1 << Character.getType(c))
+					      & PRINT_BITS) != 0
+					     && c != ' ';
+				    break;
+				case STR_IS_PRINT:
+				    result = ((1 << Character.getType(c))
+					      & PRINT_BITS) != 0;
+				    break;
+				case STR_IS_PUNCT:
+				    result = ((1 << Character.getType(c))
+					      & PUNCT_BITS) != 0;
+				    break;
+				case STR_IS_UPPER:
+				    result = Character.isUpperCase(c);
+				    break;
+				case STR_IS_SPACE:
+				    result = Character.isWhitespace(c);
+				    break;
+				case STR_IS_CONTROL:
+				    result = Character.isISOControl(c);
+				    break;
+				case STR_IS_LOWER:
+				    result = Character.isLowerCase(c);
+				    break;
+				case STR_IS_WORD:
+				    result = ((1 << Character.getType(c))
+					      & WORD_BITS) != 0;
+				    break;
+				case STR_IS_XDIGIT:
+				    result = Character.digit(c, 16) >= 0;
+				    break;
+				default:
+				    throw new TclRuntimeError("unimplemented");
+			    }
+			    if (!result) {
 				break;
-			    default:
-				throw new TclRuntimeError("unimplemented");
-			}
-			if (!result) {
-			    break;
+			    }
 			}
 		    }
 		}