Bug 559438 - Decompiler bug with JSOP_CONCATN. r=shaver.

js/src/jsopcode.cpp

@@ -3551,7 +3551,7 @@ Decompile(SprintStack *ss, jsbytecode *pc, intN nb, JSOp nextop)
                 ok = JS_FALSE;
 
                 for (i = argc - 1; i >= 0; i--) {
-                    argv[i] = JS_strdup(cx, POP_STR());
+                    argv[i] = JS_strdup(cx, POP_STR_PREC(cs->prec + 1));
                     if (!argv[i])
                         goto out;
                 }

js/src/tests/js1_8_5/regress/jstests.list

@@ -10,3 +10,4 @@ script regress-541455.js
 script regress-546615.js
 script regress-555246-0.js
 fails script regress-555246-1.js
+script regress-559438.js

js/src/tests/js1_8_5/regress/regress-559438.js

@@ -0,0 +1,10 @@
+/*
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/licenses/publicdomain/
+ * Contributor: Jason Orendorff
+ */
+
+function f(x) { return 1 + "" + (x + 1); }
+reportCompare("12", f(1), "");
+var g = eval(String(f));
+reportCompare("12", f(1), "");