Index: openacs-4/packages/acs-bootstrap-installer/tcl/00-proc-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-bootstrap-installer/tcl/00-proc-procs.tcl,v
diff -u -r1.66.2.6 -r1.66.2.7
--- openacs-4/packages/acs-bootstrap-installer/tcl/00-proc-procs.tcl	20 Jan 2020 13:11:34 -0000	1.66.2.6
+++ openacs-4/packages/acs-bootstrap-installer/tcl/00-proc-procs.tcl	31 Jan 2020 18:23:50 -0000	1.66.2.7
@@ -116,9 +116,13 @@
     #
     # Check if this looks like a switch:
     #   - first character is '-'
-    #   - next character is not a number
+    #   - next character is not a Tcl number
+    #   - next string is a printable character
     #
-    return [expr {[regexp {^-[^0-9].*$} $str]}]
+    return [expr {[string index $str 0] eq "-"
+              && ![string is double -strict $str]
+              && [regexp {^-[[:graph:]]+$} $str]
+    }]
 }
 
 proc ad_proc args {