check !foreign before attempting string_match()

Author: MichaelChirico

R/test.data.table.R

@@ -483,7 +483,7 @@ test = function(num,x,y=TRUE,error=NULL,warning=NULL,message=NULL,output=NULL,no
     out = paste(out, collapse="\n")
     output = paste(output, collapse="\n")  # so that output= can be either a \n separated string, or a vector of strings.
     # it also happens to turn off the 'y' checking branch below
-    if (length(output) && !string_match(output, out) && !foreign) {
+    if (length(output) && !foreign && !string_match(output, out)) {
       # nocov start
       catf("Test %s did not produce correct output:\n", numStr)
       catf("Expected: <<%s>>\n", encodeString(output))  # \n printed as '\\n' so the two lines of output can be compared vertically