Merge 9.0. Bug [cb03e57a] - raise error on empty regexp for unresolved variable.

Author: apnadkarni

doc/chan.n

@@ -809,7 +809,7 @@ Instruct Tcl to always send output to \fBstdout\fR immediately,
 whether or not it is to a terminal:
 .PP
 .CS
-\fBfconfigure\fR stdout -buffering none
+\fBchan configure\fR stdout -buffering none
 .CE
 .PP
 In the following example a file is opened using the encoding CP1252, which is

generic/tclCompCmdsGR.c

@@ -2447,14 +2447,11 @@ TclCompileRegexpCmd(
 	    return TCL_ERROR;
 	}
 
-	if (len == 0) {
-	    /*
-	     * The semantics of regexp are always match on re == "".
-	     */
-
-	    PUSH(		"1");
-	    return TCL_OK;
-	}
+	/*
+	 * Note: do not optimize for len == 0, as error should be generated
+	 * at runtime if operand is not a resolvable variable.
+	 * Bug https://core.tcl-lang.org/tcl/info/cb03e57a7b24d22c
+	 */
 
 	/*
 	 * Attempt to convert pattern to glob.  If successful, push the

tests/binary.test

@@ -3049,9 +3049,27 @@ test binary-80.4 {Tcl_GetBytesFromObj} -constraints testbytestring -returnCodes
     testbytestring [testbytestring "\xC0\x80\xA0\xA0\xA0\xF0\x9F\x98\x81"]
 } -result "expected byte sequence but character 4 was '\U01F601' (U+01F601)"
 test binary-80.5 {Tcl_GetBytesFromObj} -constraints {
-	bigmem testbytestring pointerIs64bit deprecated
+    bigmem testbytestring pointerIs64bit deprecated
 } -body {
-    testbytestring [string repeat A [expr 2**31]]
+    # dynamic constraint - ensure the data segment is large enough on this box for this test:
+    if {
+      [testConstraint unix] &&
+      ![catch { exec sh -c {ulimit -d} } dssz] &&
+      $dssz ne "unlimited" && $dssz <= 4400000
+    } {
+	tcltest::Skip "DBIGMEM: too small data seg size limit ($dssz <= 4400000)"
+    }
+    # dynamic constraint - ensure we're able to allocate such large block:
+    if {[catch { string repeat A [expr 2**31] } ret opt]} {
+	if {[string match "*unable to alloc*" $ret]} {
+	    tcltest::Skip "DBIGMEM: $ret"
+	}
+	return {*}$opt $ret
+    }
+    # test:
+    testbytestring $ret
+} -cleanup {
+    unset -nocomplain opt ret dssz
 } -returnCodes 1 -result "byte sequence length exceeds INT_MAX"
 
 # ----------------------------------------------------------------------

tests/regexp.test

@@ -1199,6 +1199,11 @@ test regexp-27.12 {regsub -command representation smash} {
     set s {list (.+)}
     regsub -command $s {list list} $s
 } {(.+) {list list} list}
+
+test regexp-28.1 {bug cb03e57a7b} -returnCodes error -body {
+	regexp {} $nosuchvar
+} -result {can't read "nosuchvar": no such variable}
+
 
 # cleanup
 ::tcltest::cleanupTests