[WWcvs] webwork2: if input to trim_spaces is empty or blank return empty string (Prevents warning messages on substitution)

[Mike G. v. a. <we...@ma...>]

Log Message:
-----------
if input to trim_spaces is empty or blank return empty string

(Prevents warning messages on substitution)

Tags:
----
rel-2-4-patches

Modified Files:
--------------
    webwork2/lib/WeBWorK:
        Utils.pm

Revision Data
-------------
Index: Utils.pm
===================================================================
RCS file: /webwork/cvs/system/webwork2/lib/WeBWorK/Utils.pm,v
retrieving revision 1.79.2.1.2.1
retrieving revision 1.79.2.1.2.2
diff -Llib/WeBWorK/Utils.pm -Llib/WeBWorK/Utils.pm -u -r1.79.2.1.2.1 -r1.79.2.1.2.2
--- lib/WeBWorK/Utils.pm
+++ lib/WeBWorK/Utils.pm
@@ -740,6 +740,7 @@
 ## Utility function to trim whitespace off the start and end of its input
 sub trim_spaces {
 	my $in = shift;
+	return '' unless $in;  # skip blank spaces
 	$in =~ s/^\s*(.*?)\s*$/$1/;
 	return($in);
 }