*** generic/tclGet.c.orig	Mon Sep 14 20:39:58 1998
--- generic/tclGet.c	Wed Jul 14 19:43:00 1999
***************
*** 71,77 ****
          if (interp != (Tcl_Interp *) NULL) {
              Tcl_AppendResult(interp, "expected integer but got \"", string,
                      "\"", (char *) NULL);
!         }
  	return TCL_ERROR;
      }
  
--- 71,78 ----
          if (interp != (Tcl_Interp *) NULL) {
              Tcl_AppendResult(interp, "expected integer but got \"", string,
                      "\"", (char *) NULL);
! 	    TclCheckBadOctal(interp, p);
! 	}
  	return TCL_ERROR;
      }
  
***************
*** 155,160 ****
--- 156,162 ----
          if (interp != (Tcl_Interp *) NULL) {
              Tcl_AppendResult(interp, "expected integer but got \"", string,
                      "\"", (char *) NULL);
+ 	    TclCheckBadOctal(interp, p);
          }
  	return TCL_ERROR;
      }
*** generic/tclObj.c.orig	Tue Oct 06 00:32:08 1998
--- generic/tclObj.c	Wed Jul 14 19:43:40 1999
***************
*** 1741,1746 ****
--- 1741,1747 ----
  	    sprintf(buf, "expected integer but got \"%.50s\"", string);
  	    Tcl_ResetResult(interp);
  	    Tcl_AppendToObj(Tcl_GetObjResult(interp), buf, -1);
+ 	    TclCheckBadOctal(interp, p);
  	}
  	return TCL_ERROR;
      }
*** generic/tclExecute.c.orig	Thu Nov 19 21:10:50 1998
--- generic/tclExecute.c	Thu Jul 15 14:15:44 1999
***************
*** 3148,3153 ****
--- 3148,3156 ----
  		    "floating-point value" : "non-numeric string"),
  		" as operand of \"", operatorStrings[opCode - INST_LOR],
  		"\"", (char *) NULL);
+ 	if (opndPtr->typePtr != &tclDoubleType) {
+ 	    TclCheckBadOctal(interp, Tcl_GetStringFromObj(opndPtr, NULL));
+ 	}
      }
  }
  
*** generic/tclUtil.c.orig	Wed Jul 14 19:36:40 1999
--- generic/tclUtil.c	Thu Jul 15 14:56:36 1999
***************
*** 2807,2818 ****
--- 2807,2871 ----
  		Tcl_AppendStringsToObj(Tcl_GetObjResult(interp),
  			"bad index \"", bytes,
  			"\": must be integer or \"end\"", (char *) NULL);
+ 		TclCheckBadOctal(interp, bytes);
  	    }
  	    return result;
  	}
      }
      *indexPtr = index;
      return TCL_OK;
+ }
+ 
+ /*
+  *----------------------------------------------------------------------
+  *
+  * TclCheckBadOctal --
+  *
+  *	This procedure checks for a bad octal value and appends a
+  *	meaningful error to the interp's result.
+  *
+  * Results:
+  *	1 if the argument was a bad octal, else 0.
+  *
+  * Side effects:
+  *	The interpreter's result is modified.
+  *
+  *----------------------------------------------------------------------
+  */
+ 
+ int
+ TclCheckBadOctal(interp, value)
+      Tcl_Interp *interp;	/* Interpreter to use for error reporting. 
+ 				 * If NULL, then no error message is left
+ 				 * after errors. */
+      char *value;		/* String to check. */
+ {
+     char *p;
+ 
+     /*
+      * A frequent mistake is invalid octal values due to an unwanted
+      * leading zero. Try to generate a meaningful error message.
+      */
+ 
+     p = value;
+     if (*p == '+' || *p == '-') {
+ 	p++;
+     }
+     if (*p == '0') {
+ 	while (isdigit(UCHAR(*p))) {
+ 	    p++;
+ 	}
+ 	if (*p == '\0') {
+ 	    /* Reached end of string */
+ 	    if (interp) {
+ 		Tcl_AppendResult(interp,
+ 		    "; \"", value, "\" uses an incorrect octal representation - see the expr man page",
+ 		    (char *) NULL);
+ 	    }
+ 	    return 1;
+ 	}
+     }
+     return 0;
  }
  
  /*
*** generic/tclCmdMZ.c.orig	Mon Sep 14 20:39:56 1998
--- generic/tclCmdMZ.c	Thu Jul 15 14:47:36 1999
***************
*** 1587,1592 ****
--- 1587,1593 ----
      Tcl_Obj *patternObj, *bodyObj;
      char *string, *pattern, *body;
      int splitObjs, length, patternLen, i, code, mode, matched, bodyIdx;
+     int seenComment;
      static char *switches[] =
  	    {"-exact", "-glob", "-regexp", "--", (char *) NULL};
  
***************
*** 1647,1657 ****
--- 1648,1670 ----
  	splitObjs = 1;
      }
  
+     seenComment = 0;
      for (i = 0;  i < switchObjc;  i += 2) {
  	if (i == (switchObjc-1)) {
  	    Tcl_ResetResult(interp);
  	    Tcl_AppendToObj(Tcl_GetObjResult(interp),
  	            "extra switch pattern with no body", -1);
+ 
+ 	    /*
+ 	     * Check if this can be due to a badly placed comment
+ 	     * in the switch block
+ 	     */
+ 
+ 	    if (splitObjs && seenComment) {
+ 		Tcl_AppendToObj(Tcl_GetObjResult(interp),
+ 			"; this can be due to a comment incorrectly placed outside a switch body - see the Tcl and switch man pages", -1);
+ 	    }
+ 
  	    code = TCL_ERROR;
  	    goto done;
  	}
***************
*** 1668,1673 ****
--- 1681,1696 ----
  	    pattern = Tcl_GetStringFromObj(patternObj, &patternLen);
  	} else {
  	    pattern = Tcl_GetStringFromObj(switchObjv[i], &patternLen);
+ 	}
+ 
+ 	/*
+ 	 * The following is an heuristic to detect the infamous
+ 	 * "comment in switch" error: just check if a pattern
+ 	 * begins with '#'.
+ 	 */
+ 
+ 	if (*pattern == '#') {
+ 	    seenComment = 1;
  	}
  
  	matched = 0;
*** generic/tclInt.h.orig	Wed Feb 03 22:28:00 1999
--- generic/tclInt.h	Wed Jul 14 19:42:12 1999
***************
*** 1427,1432 ****
--- 1427,1434 ----
  EXTERN void		TclAllocateFreeObjects _ANSI_ARGS_((void));
  EXTERN int		TclChdir _ANSI_ARGS_((Tcl_Interp *interp,
  			    char *dirName));
+ EXTERN int		TclCheckBadOctal _ANSI_ARGS_((Tcl_Interp *interp,
+ 			    char *value));
  EXTERN int		TclCleanupChildren _ANSI_ARGS_((Tcl_Interp *interp,
  			    int numPids, Tcl_Pid *pidPtr,
  			    Tcl_Channel errorChan));