lseq bugfixes: 8d1fc7,999b69,tip-746

changes.md

@@ -14,7 +14,12 @@ to the userbase.
  - [Check for -municode doesn't work on WSL](https://core.tcl-lang.org/tcl/tktview/632710)
  - [configure --enable-man-compression error](https://core.tcl-lang.org/tcl/tktview/886549)
  - [nmake: rmdir and mkdir are picked from cygwin if available](https://core.tcl-lang.org/tcl/tktview/be40b7)
-
+ - [lseq: has incorrect results in edge cases](https://core.tcl-lang.org/tcl/tktview/999b69)
+ - [lseq: "count" error persists across calls](https://core.tcl-lang.org/tcl/tktview/8d1fc7)
+ - [lseq: tip-746 removes the ability to pass expressions as numeric
+   values in the lseq
+   command.](https://core.tcl-lang.org/tips/doc/trunk/tip/746.md)
+   
 # Updated bundled packages, libraries, standards, data
  - Itcl 4.3.6
  - sqlite3 3.51.2

doc/lseq.n

@@ -31,40 +31,48 @@ The \fBlseq\fR command can produce both increasing and decreasing
 sequences. When both \fIstart\fR and \fIend\fR are provided without a
 \fIstep\fR value, then if \fIstart\fR <= \fIend\fR, the sequence will be
 increasing and if \fIstart\fR > \fIend\fR it will be decreasing. If a
-\fIstep\fR vale is included, it's sign should agree with the direction of the
-sequence (descending \(-> negative and ascending \(-> positive), otherwise an
-empty list is returned.  For example:
+\fIstep\fR value is included, it's sign should agree with the direction of the
+sequence (descending \(-> negative and ascending \(-> positive), otherwise the
+list will have a length of 0.  For example:
 .RS
 .PP
 .CS \"
-% \fBlseq\fR 1 to 5    ;# increasing
+# increasing:
+.br
+% \fBlseq\fR 1 to 5
 \fI\(-> 1 2 3 4 5
 
-% \fBlseq\fR 5 to 1    ;# decreasing
+# decreasing:
+.br
+% \fBlseq\fR 5 to 1
 \fI\(-> 5 4 3 2 1
 
-% \fBlseq\fR 0 0.5 by 0.1  ;# doubles
+# doubles:
+.br
+% \fBlseq\fR 0 0.5 by 0.1
 \fI\(-> 0.0 0.1 0.2 0.3 0.4 0.5\fR
 
-% \fBlseq\fR 6 to 1 by 2   ;# decreasing, step wrong sign, empty list
+# decreasing, step with wrong sign:
+.br
+% \fBlseq\fR 6 to 1 by 2
+\fI\(-> {}
 
-% \fBlseq\fR 1 to 5 by 0   ;# all step sizes of 0 produce an empty list
+# step of 0,
+.br
+% \fBlseq\fR 3 to 9 by 0
+\fI\(-> 3
 .\"
 .CE
 .RE
 .PP
-The numeric arguments, \fIstart\fR, \fIend\fR, \fIstep\fR, and \fIcount\fR,
-may also be a valid expression. The expression will be evaluated and the
-numeric result will be used.  An expression that does not evaluate to a number
-will produce an invalid argument error.
-.PP
 \fIStart\fR defines the initial value and \fIend\fR defines the limit, not
 necessarily the last value. \fBlseq\fR produces a list with \fIcount\fR
-elements, and if \fIcount\fR is not supplied, it is computed as:
+elements, always, even if the step value is 0. and if \fIcount\fR is not
+supplied, it is computed as:
 .RS
 .PP
 .CS
-\fIcount\fR = int( (\fIend\fR - \fIstart\fR + \fIstep\fR) / \fIstep\fR )
+\fIcount\fR = int( ( (\fIend\fR - \fIstart\fR) / \fIstep\fR ) + 1 )
 .CE
 .RE
 .SH EXAMPLES
@@ -82,6 +90,9 @@ elements, and if \fIcount\fR is not supplied, it is computed as:
 set l [\fBlseq\fR 0 -5]
 \fI\(-> 0 -1 -2 -3 -4 -5\fR
 
+\fBlseq\fR 1 count 5 by 0
+\fI\(-> 1 1 1 1 1\fR
+
 foreach i [\fBlseq\fR [llength $l]] {
     puts l($i)=[lindex $l $i]
 }
@@ -103,13 +114,13 @@ foreach i [\fBlseq\fR {[llength $l]-1} 0] {
 \fI\(-> l(0)=0\fR
 
 set i 17
-         \fI\(-> 17\fR
+\fI\(-> 17\fR
+
 if {$i in [\fBlseq\fR 0 50]} { # equivalent to: (0 <= $i && $i <= 50)
     puts "Ok"
 } else {
     puts "outside :("
-}
-\fI\(-> Ok\fR
+} \fI\(-> Ok\fR
 
 set sqrs [lmap i [\fBlseq\fR 1 10] { expr {$i*$i} }]
 \fI\(-> 1 4 9 16 25 36 49 64 81 100\fR

generic/tclArithSeries.c

@@ -289,6 +289,13 @@ maxObjPrecision(
  *----------------------------------------------------------------------
  */
 static Tcl_WideInt
+ArithSeriesLenDbl(
+    double start,
+    double end,
+    double step,
+    unsigned precision);
+
+static Tcl_WideInt
 ArithSeriesLenInt(
     Tcl_WideInt start,
     Tcl_WideInt end,
@@ -296,13 +303,21 @@ ArithSeriesLenInt(
 {
     Tcl_WideInt len;
 
+    // Check for opposite sequence directions
+    if ((step < 0 && (end-start) > 0) ||
+        (step > 0 && (end-start) < 0)) {
+        return 0;
+    }
     if (step == 0) {
-	return 0;
+        // Sequence consists of a single value
+	return 1;
     }
-    len = (end - start) / step + 1;
+
+    len = ((end - start) / step) + 1;
     if (len < 0) {
-	return 0;
+	len = 0;
     }
+
     return len;
 }
 
@@ -320,7 +335,7 @@ ArithSeriesLenDbl(
 			  * with and w/o FPU_INLINE_ASM, _CONTROLFP, etc) */
 
     if (step == 0) {
-	return 0;
+	return 1;
     }
     if (precision) {
 	scaleFactor = power10(precision);
@@ -330,6 +345,7 @@ ArithSeriesLenDbl(
     }
     /* distance */
     end -= start;
+
     /*
      * To improve numerical stability use wide arithmetic instead of IEEE-754
      * when distance and step do not exceed wide-integers.
@@ -339,7 +355,8 @@ ArithSeriesLenDbl(
 	Tcl_WideInt iend = end < 0 ? end - 0.5 : end + 0.5;
 	Tcl_WideInt istep = step < 0 ? step - 0.5 : step + 0.5;
 	if (istep) { /* avoid div by zero, steps like 0.1, precision 0 */
-	    return (iend / istep) + 1;
+	    Tcl_WideInt ilen = (iend / istep) + 1;
+	    return (ilen < 0 ? 0 : ilen);
 	}
     }
     /*
@@ -348,10 +365,10 @@ ArithSeriesLenDbl(
      */
     len = (end / step) + 1;
     if (len >= (double)TCL_SIZE_MAX) {
-	return TCL_SIZE_MAX;
+	len = TCL_SIZE_MAX;
     }
-    if (len < 0) {
-	return 0;
+    if (len <= 0) {
+	len = 1;
     }
     return (Tcl_WideInt)len;
 }
@@ -460,10 +477,13 @@ NewArithSeriesInt(
 
     TclNewObj(arithSeriesObj);
 
-    if (length <= 0) {
-	/* TODO - should negative lengths be an error? */
+    if (length < 0) {
+	// Negative length implies the step direction is opposite to the
+	// start/end direction. In mathmatical terms, an infinite length.
+        // Map this to an empty list (length of 0). An empty set is a vaild
+	// sequence.
 	return arithSeriesObj;
-    } else if (length > 1) {
+    } else if (length >= 1) {
 	/* Check for numeric overflow. Not needed for single element lists */
 	Tcl_WideUInt absoluteStep;
 	Tcl_WideInt numIntervals = length - 1;
@@ -481,9 +501,10 @@ NewArithSeriesInt(
 	    absoluteStep = -step;
 	}
 	/* First, step*number of intervals should not overflow */
-	if ((UWIDE_MAX / absoluteStep) < (Tcl_WideUInt) numIntervals) {
+	if (absoluteStep && (UWIDE_MAX / absoluteStep) < (Tcl_WideUInt) numIntervals) {
 	    goto invalid_range;
 	}
+        
 	if (step > 0) {
 	    /*
 	     * Because of check above and UWIDE_MAX=2*WIDE_MAX+1,
@@ -675,53 +696,61 @@ TclNewArithSeriesObj(
 {
     double dstart, dend, dstep = 1.0;
     Tcl_WideInt start, end, step = 1;
-    Tcl_WideInt len = -1;
+    Tcl_WideInt len;
     Tcl_Obj *objPtr;
     unsigned precision = (unsigned)-1; /* unknown precision */
 
+
+    if (lenObj) {
+	if (Tcl_GetWideIntFromObj(interp, lenObj, &len) != TCL_OK) {
+	    return NULL;
+	}
+    } else {
+	// Default
+	len = -1;
+    }
+
+    if (stepObj) {
+	if (assignNumber(interp, useDoubles, &step, &dstep, stepObj) != TCL_OK) {
+	    return NULL;
+	}
+    } else {
+	// Default
+	step = 1;
+	dstep = step;
+    }
+
     if (startObj) {
 	if (assignNumber(interp, useDoubles, &start, &dstart, startObj) != TCL_OK) {
 	    return NULL;
 	}
     } else {
+	// Default
 	start = 0;
-	dstart = 0.0;
-    }
-    if (stepObj) {
-	if (assignNumber(interp, useDoubles, &step, &dstep, stepObj) != TCL_OK) {
-	    return NULL;
-	}
-	if (!useDoubles ? !step : !dstep) {
-	    TclNewObj(objPtr);
-	    return objPtr;
-	}
+	dstart = start;
     }
+
     if (endObj) {
 	if (assignNumber(interp, useDoubles, &end, &dend, endObj) != TCL_OK) {
 	    return NULL;
 	}
     }
-    if (lenObj) {
-	if (Tcl_GetWideIntFromObj(interp, lenObj, &len) != TCL_OK) {
-	    return NULL;
-	}
-    }
 
     if (endObj) {
 	if (!stepObj) {
 	    if (useDoubles) {
 		if (dstart > dend) {
-		    dstep = -1.0;
 		    step = -1;
+		    dstep = step;
 		}
 	    } else {
 		if (start > end) {
 		    step = -1;
-		    dstep = -1.0;
+		    dstep = step;
 		}
 	    }
 	}
-	assert(dstep!=0);
+
 	if (!lenObj) {
 	    if (useDoubles) {
 		if (isinf(dstart) || isinf(dend)) {
@@ -763,6 +792,13 @@ TclNewArithSeriesObj(
      * similar to plain lists, otherwise it'd generate an error or panic later
      * (0x0ffffffffffffffa instead of 0x7fffffffffffffff by 64bit)
      */
+    /*
+     * Comment for future reference: The size concern would only be triggered
+     * via a shimmer or getElements of the abstract list. Otherwise, the
+     * abstract list is only limited by the max index value. Even then,
+     * indexing with a bignum is theoretically possible. This is because
+     * individual values are not stored. They are created upon request.
+     */
     if (len > TCL_SIZE_MAX) {
     exceeded:
 	Tcl_SetObjResult(interp, Tcl_NewStringObj(

generic/tclCmdIL.c

@@ -4047,10 +4047,6 @@ SequenceIdentifyArgument(
     void *internalPtr;
 
     if (allowedArgs & NumericArg) {
-	/* speed-up a bit (and avoid shimmer for compiled expressions) */
-	if (TclHasInternalRep(argPtr, &tclExprCodeType)) {
-	   goto doExpr;
-	}
 	result = Tcl_GetNumberFromObj(NULL, argPtr, &internalPtr, keywordIndexPtr);
 	if (result == TCL_OK) {
 	    *numValuePtr = argPtr;
@@ -4072,24 +4068,15 @@ SequenceIdentifyArgument(
 	*keywordIndexPtr = opmode;
 	return RangeKeywordArg;
     } else {
-	Tcl_Obj *exprValueObj;
+	int keyword;
 	if (!(allowedArgs & NumericArg)) {
 	    return NoneArg;
 	}
-    doExpr:
-	/* Check for an index expression */
-	if (Tcl_ExprObj(interp, argPtr, &exprValueObj) != TCL_OK) {
+	if (Tcl_GetNumberFromObj(interp, argPtr, &internalPtr, &keyword) != TCL_OK) {
 	    return ErrArg;
 	}
-	int keyword;
-	/* Determine if result of expression is double or int */
-	if (Tcl_GetNumberFromObj(interp, exprValueObj, &internalPtr,
-		&keyword) != TCL_OK
-	) {
-	    return ErrArg;
-	}
-	*numValuePtr = exprValueObj; /* incremented in Tcl_ExprObj */
-	*keywordIndexPtr = keyword; /* type of expression result */
+	*numValuePtr = argPtr;
+	*keywordIndexPtr = keyword; /* type of result */
 	return NumericArg;
     }
 }

tests/lseq.test

@@ -19,6 +19,7 @@ testConstraint arithSeriesShimmer 1
 testConstraint arithSeriesShimmerOk 1
 testConstraint has64BitLengths [expr {$tcl_platform(pointerSize) == 8}]
 testConstraint has32BitLengths [expr {$tcl_platform(pointerSize) == 4}]
+testConstraint TIP746 0 ;# Obsolete expr behavior in lseq on numeric arguments
 
 proc memusage {} {
     set fd [open /proc/[pid]/statm]
@@ -154,35 +155,30 @@ test lseq-1.24 {consistence, use double (even if representable as integer) in al
 	 [lseq 0 count 3 by 1.0] [lseq 0 .. 2.0] [lseq 0 to 2 by 1.0]
 } [lrepeat 6 {0.0 1.0 2.0}]
 test lseq-1.25 {consistence, use double (even if representable as integer) in all variants, if contains a double somewhere} {
-    list [lseq double(0) 2] [lseq 0 double(2)] [lseq double(0) count 3] \
-	 [lseq 0 count 3 by double(1)] [lseq 0 .. double(2)] [lseq 0 to 2 by double(1)]
+    list [lseq [expr {double(0)}] 2] [lseq 0 [expr {double(2)}]] [lseq [expr {double(0)}] count 3] \
+        [lseq 0 count 3 by [expr {double(1)}]] [lseq 0 .. [expr {double(2)}]] [lseq 0 to 2 by [expr {double(1)}]]
 } [lrepeat 6 {0.0 1.0 2.0}]
 test lseq-1.26 {consistence, double always remains double} {
     list [lseq        1              3.0      ] \
 	 [lseq        1       [expr {3.0+0}]  ] \
-	 [lseq        1             {3.0+0}   ] \
 	 [lseq        1.0            3.0     1] \
-	 [lseq [expr {1.0+0}] [expr {3.0+0}] 1] \
-	 [lseq       {1.0+0}        {3.0+0}  1]
-} [lrepeat 6 {1.0 2.0 3.0}]
+	 [lseq [expr {1.0+0}] [expr {3.0+0}] 1]
+} [lrepeat 4 {1.0 2.0 3.0}]
 test lseq-1.27 {consistence, double always remains double} {
     list [lseq        1e50     [expr {1e50+1}]  ] \
-	 [lseq        1e50           {1e50+1}   ] \
 	 [lseq [expr {1e50+0}] [expr {1e50+1}] 1] \
-	 [lseq       {1e50+0}        {1e50+1}  1] \
-	 [lseq [expr {1e50+0}] count 1 1] \
-	 [lseq       {1e50+0}  count 1 1]
-} [lrepeat 6 [expr {1e50}]]
+	 [lseq [expr {1e50+0}] count 1 1]
+} [lrepeat 3 [expr {1e50}]]
 
 #
 # Short-hand use cases
 #
 test lseq-2.2 {step magnitude} {
-    lseq 10 1 2 ;# this is an empty case since step has wrong sign
+    lseq 10 1 2 ;# An error where step has wrong sign. Not an error, but list has len 1
 } {}
 
 test lseq-2.3 {step wrong sign} arithSeriesDouble {
-    lseq 25. 5. 5 ;# ditto - empty list
+    lseq 25. 5. 5 ;# ditto - same as lseq-2.2 above
 } {}
 
 test lseq-2.4 {integer decreasing} {
@@ -215,7 +211,7 @@ test lseq-2.10 {integer lseq with step} {
     lseq 1 10 2
 } {1 3 5 7 9}
 
-test lseq-2.11 {error case: increasing wrong step direction} {
+test lseq-2.11 {case: increasing wrong step direction} {
     lseq 1 10 -2
 } {}
 
@@ -255,20 +251,20 @@ test lseq-2.18 {signs} {
 
 } {{-10 -8 -6 -4 -2} {} {} {10 6 2} {-10 -7 -4 -1} {10 5}}
 
-test lseq-2.19 {expressions as indices} {
+test lseq-2.19 {expressions as indices} -constraints TIP746 -body {
     list [lseq {1+1}] \
 	 [lseq {1+1} {2+2}] \
 	 [lseq {1+1} count {2+2}] \
 	 [lseq {1+1} {5+5} {2+2}] \
 	 [lseq {1+1} count {2+2} by {2+2}]
-} {{0 1} {2 3 4} {2 3 4 5} {2 6 10} {2 6 10 14}}
+} -result {{0 1} {2 3 4} {2 3 4 5} {2 6 10} {2 6 10 14}}
 
-test lseq-2.20 {expressions as indices, no duplicative eval of expr} {
+test lseq-2.20 {expressions as indices, no duplicative eval of expr} -constraints TIP746 -body {
     set i 1
     list [lseq {[incr i]}] $i [lseq {0 + [incr i]}] $i [lseq {0.0 + [incr i]}] $i
-} {{0 1} 2 {0 1 2} 3 {0 1 2 3} 4}
+} -result {{0 1} 2 {0 1 2} 3 {0 1 2 3} 4}
 
-test lseq-3.0 {expr error: don't swalow expr error (here: divide by zero)} -body {
+test lseq-3.0 {expr error: don't swalow expr error (here: divide by zero)} -constraints TIP746 -body {
     set i 0; lseq {3/$i}
 } -returnCodes [catch {expr {3/0}} res] -result $res
 
@@ -296,15 +292,15 @@ test lseq-3.1 {experiement} -body {
 
 test lseq-3.2 {error case} -body {
     lseq foo
-} -returnCodes 1 -match glob -result {invalid bareword "foo"*}
+} -returnCodes 1 -match glob -result {expected number but got "foo"}
 
 test lseq-3.3 {error case} -body {
     lseq 10 foo
-} -returnCodes 1 -match glob -result {invalid bareword "foo"*}
+} -returnCodes 1 -match glob -result {expected number but got "foo"}
 
 test lseq-3.4 {error case} -body {
     lseq 25 or 6
-} -returnCodes 1 -match glob -result {invalid bareword "or"*}
+} -returnCodes 1 -match glob -result {expected number but got "or"}
 
 test lseq-3.5 {simple count and step arguments} -body {
     set s [lseq 25 by 6]
@@ -421,14 +417,24 @@ test lseq-3.18 {error case} -body {
 
 test lseq-3.19 {edge case} -body {
     lseq 1 count 5 by 0
-} -result {}
-# 1 1 1 1 1
+} -result {1 1 1 1 1}
 
-# My thought is that this is likely a user error, since they can always use lrepeat for this.
+# My thought is that this is likely a user error, since they can
+# always use lrepeat for this.
+
+# bsg: Nah. The count defines the required list length, regardless of
+#           the values produced by the equation.  Consider scenarios
+#           where arguments are variables that may include 0
+#           intentionally. A reasonable valid answer is better than
+#           always having to safeguard against errors.
+#
+#      Another way to look at it is that the sequence is an equation
+#      of a straight line. Every sequnce should be representable on a
+#      cartisian plane where X (the index) is always positive.
 
 test lseq-3.20 {edge case} -body {
     lseq 1 to 1 by 0
-} -result {}
+} -result {1}
 
 # hmmm, I guess this is right, in a way, so...
 
@@ -556,7 +562,7 @@ test lseq-3.34 {"in" operator} -body {
 } -result {{3012.0 3012.3 3012.6 3012.9} {3012.03 3012.06 3012.09 3012.12 3012.15 3012.18 3012.21 3012.24 3012.27 3012.33 3012.36 3012.39 3012.42 3012.45 3012.48 3012.51 3012.54 3012.57 3012.63 3012.66 3012.69 3012.72 3012.75 3012.78 3012.81 3012.84 3012.87 3012.93 3012.96 3012.99}}
 
 test lseq-3.35 {"in" operator integer} -body {
-    set seq [lseq 3 int(15e4) 5]
+    set seq [lseq 3 [expr {int(15e4)}] 5]
     set inlist {}
     set nilist {}
     foreach y [lseq 3012 3213 3] {
@@ -584,12 +590,12 @@ test lseq-3.36 {"in" non-numeric case} -body {
 
 test lseq-4.1 {end expressions} -body {
     set start 7
-    lseq $start $start+11
+    lseq $start [expr {$start+11}]
 } -cleanup {unset start} -result {7 8 9 10 11 12 13 14 15 16 17 18}
 
 test lseq-4.2 {start expressions} -body {
     set base [clock seconds]
-    set tl [lseq $base-60 $base 10]
+    set tl [lseq [expr {$base-60}] $base 10]
     lmap t $tl {expr {$t - $base + 60}}
 } -cleanup {unset base tl t} -result {0 10 20 30 40 50 60}
 
@@ -620,11 +626,11 @@ test lseq-4.3 {TIP examples} -body {
 	lseq 25. to -25. by -5
 	# -> 25.0 20.0 15.0 10.0 5.0 0.0 -5.0 -10.0 -15.0 -20.0 -25.0
 	lseq 5 5
-	# -> 5
+	# ->
 	lseq 5 5 2
-	# -> 5
+	# ->
 	lseq 5 5 -2
-	# -> 5
+	# ->
     }
     set res {}
     foreach {cmd expect} [split $examples \n] {
@@ -852,7 +858,7 @@ test lseq-4.21.1 {Corner cases: overflows by Inf} -body {
 }]
 test lseq-4.21.2 {Corner cases: expected Inf} -body {
     set res {}
-    lappend res [lseq {1e5555+0} count 5]
+    lappend res [lseq [expr {1e5555+0}] count 5]
     lappend res [lseq Inf count 5]
     lappend res [lseq Inf count 5 by 100]
     lappend res [lseq Inf count 5 by Inf]
@@ -878,7 +884,7 @@ test lseq-4.21.2 {Corner cases: expected Inf} -body {
 }]
 test lseq-4.21.3 {Corner cases: expected -Inf} -body {
     set res {}
-    lappend res [lseq {-1e5555+0} count 5]
+    lappend res [lseq [expr {-1e5555+0}] count 5]
     lappend res [lseq -Inf count 5]
     lappend res [lseq -Inf count 5 by 100]
     lappend res [lseq -Inf count 5 by -Inf]
@@ -906,7 +912,7 @@ test lseq-4.21.4 {Corner cases: unexpected Inf - Inf, result to +/-NaN, unexpect
     set res {}
     lappend res [list [catch {lseq Inf count 5 by -Inf} msg opt] $msg [dict getd $opt -errorcode ""]]
     lappend res [list [catch {lseq -Inf count 5 by Inf} msg opt] $msg [dict getd $opt -errorcode ""]]
-    lappend res [list [catch {lseq {Inf - Inf} count 5} msg opt] $msg [dict getd $opt -errorcode ""]]
+    lappend res [list [catch {lseq [expr {Inf - Inf}] count 5} msg opt] $msg [dict getd $opt -errorcode ""]]
     lappend res [list [catch {lseq NaN count 5}         msg opt] $msg [dict getd $opt -errorcode ""]]
     lappend res [list [catch {lseq NaN count 5 by 100}  msg opt] $msg [dict getd $opt -errorcode ""]]
     lappend res [list [catch {lseq NaN count 5 by NaN}  msg opt] $msg [dict getd $opt -errorcode ""]]
@@ -916,6 +922,7 @@ test lseq-4.21.4 {Corner cases: unexpected Inf - Inf, result to +/-NaN, unexpect
 } -cleanup {
     unset -nocomplain res msg opt
 } -result [join [lrepeat 8 {1 {domain error: argument not in valid range} {ARITH DOMAIN {domain error: argument not in valid range}}}] \n]
+
 test lseq-4.21.5 {Corner cases: unexpected NaN} -body {
     set res {}
     lappend res [catch {lseq NaN} msg] $msg
@@ -923,6 +930,7 @@ test lseq-4.21.5 {Corner cases: unexpected NaN} -body {
 } -cleanup {
     unset -nocomplain res msg
 } -result {1 {expected integer but got "NaN"} 1 {cannot use non-numeric floating-point value "NaN" to estimate length of arith-series}}
+
 test lseq-4.21.6 {Corner cases: empty list, reversed step} -body {
     set res {}
     lappend res [lseq -5 ..  0 by -1]
@@ -932,36 +940,55 @@ test lseq-4.21.6 {Corner cases: empty list, reversed step} -body {
 } -cleanup {
     unset -nocomplain res
 } -result {{} {} {} {}}
+
 test lseq-4.21.6-lran {Corner cases: lrange empty list, reversed step} -body {
     set res {}
     # not shared:
     lappend res [lrange [lseq -5 ..  0 by -1] 1 end-1]
+    lappend res [lrange [lseq -5 ..  0 by  1] 1 end-1]
+    lappend res [lrange [lseq  5 ..  0 by -1] 1 end-1]
     lappend res [lrange [lseq  5 ..  0 by  1] 1 end-1]
     lappend res [lrange [lseq  0 ..  5 by -1] 1 end-1]
+    lappend res [lrange [lseq  0 ..  5 by  1] 1 end-1]
+    lappend res [lrange [lseq  0 .. -5 by -1] 1 end-1]
     lappend res [lrange [lseq  0 .. -5 by  1] 1 end-1]
     # shared:
     lappend res [lrange [set l [lseq -5 ..  0 by -1]] 1 end-1]
+    lappend res [lrange [set l [lseq -5 ..  0 by  1]] 1 end-1]
+    lappend res [lrange [set l [lseq  5 ..  0 by -1]] 1 end-1]
     lappend res [lrange [set l [lseq  5 ..  0 by  1]] 1 end-1]
     lappend res [lrange [set l [lseq  0 ..  5 by -1]] 1 end-1]
+    lappend res [lrange [set l [lseq  0 ..  5 by  1]] 1 end-1]
+    lappend res [lrange [set l [lseq  0 .. -5 by -1]] 1 end-1]
     lappend res [lrange [set l [lseq  0 .. -5 by  1]] 1 end-1]
 } -cleanup {
     unset -nocomplain res l
-} -result {{} {} {} {} {} {} {} {}}
+} -result {{} {-4 -3 -2 -1} {4 3 2 1} {} {} {1 2 3 4} {-1 -2 -3 -4} {} {} {-4 -3 -2 -1} {4 3 2 1} {} {} {1 2 3 4} {-1 -2 -3 -4} {}}
+
 test lseq-4.21.6-lrev {Corner cases: lreverse empty list, reversed step} -body {
     set res {}
     # not shared:
     lappend res [lreverse [lseq -5 ..  0 by -1]]
+    lappend res [lreverse [lseq -5 ..  0 by  1]]
+    lappend res [lreverse [lseq  5 ..  0 by -1]]
     lappend res [lreverse [lseq  5 ..  0 by  1]]
-    lappend res [lreverse [lseq  0 ..  5 by -1]]
+    lappend res [lreverse [lseq  0 .. -5 by -1]]
     lappend res [lreverse [lseq  0 .. -5 by  1]]
+    lappend res [lreverse [lseq  0 ..  5 by -1]]
+    lappend res [lreverse [lseq  0 ..  5 by  1]]
     # shared:
     lappend res [lreverse [set l [lseq -5 ..  0 by -1]]]
+    lappend res [lreverse [set l [lseq -5 ..  0 by  1]]]
+    lappend res [lreverse [set l [lseq  5 ..  0 by -1]]]
     lappend res [lreverse [set l [lseq  5 ..  0 by  1]]]
     lappend res [lreverse [set l [lseq  0 ..  5 by -1]]]
-    lappend res [lreverse [set l [lseq  0 .. -5 by  1]]]
+    lappend res [lreverse [set l [lseq  0 ..  5 by  1]]]
+    lappend res [lreverse [set l [lseq  0 .. -5 by -1]]]
+    lappend res [lreverse [set l [lseq  0 .. -5 by -1]]]
 } -cleanup {
     unset -nocomplain res l
-} -result {{} {} {} {} {} {} {} {}}
+} -result {{} {0 -1 -2 -3 -4 -5} {0 1 2 3 4 5} {} {-5 -4 -3 -2 -1 0} {} {} {5 4 3 2 1 0} {} {0 -1 -2 -3 -4 -5} {0 1 2 3 4 5} {} {} {5 4 3 2 1 0} {-5 -4 -3 -2 -1 0} {-5 -4 -3 -2 -1 0}}
+
 test lseq-4.21.7 {Corner cases: non-empty list, normal step} -body {
     set res {}
     lappend res [lseq -5 ..  0      ]
@@ -1116,6 +1143,17 @@ test lseq-bug-0ee626dfb2-1 {Bug 0ee626dfb2 - integer overflow} -body {
     lseq 0x7fffffffffffffff count 3 by -0x8000000000000000
 } -result {invalid arithmetic series parameter values} -returnCodes error
 
+test lseq-bug-8d1fc709957-0 {Bug 8d1fc709957 - lseq "count" error persists across calls} -body {
+    catch {lseq 0 count 5} err0
+    catch {lseq count 5} err1
+    catch {lseq 1 count 5} err2
+    list $err0 $err1 $err2
+} -result {{0 1 2 3 4} {expected number but got "count"} {1 2 3 4 5}}
+
+test lseq-bug-999b6966b2-0 {Bug 999b6966b2 - lseq has incorrect results in edge cases} -body {
+    lmap i [lseq -9 9] { lseq 10 10 $i }
+} -result {10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10}
+
 # cleanup
 ::tcltest::cleanupTests