function f() { "use strict"; return "\u00007" } print(f); print(eval(uneval(f))); typein:4: SyntaxError: octal literals and octal escape sequences are deprecated: typein:4: function f() {'use strict';return "\07";} typein:4: ..................................^ The first bad revision is: changeset: 43f456d9b632 user: Jim Blandy date: Thu Nov 19 09:49:00 2009 -0800 summary: Bug 514559: Forbid octal literals or escape sequences in strict mode. r=mrbkap

(In reply to comment #0) > function f() { "use strict"; return "\u00007" } > The first bad revision is: > changeset: 43f456d9b632 > summary: Bug 514559: Forbid octal literals or escape sequences in strict > mode. r=mrbkap This is the revision that introduced the check that caught the bug, not the revision that introduced the bug. The printer's generated string "\07", is not a valid literal in strict mode code (the rule for "\0" says that it can't be followed by a decimal digit).

It should generate "\x00" in that case, I guess.

Tricky. While "\0" is allowed in strict mode, we have to be careful about what follows being maximum-munched. Or we could lose the '\0' -> '0' pair in js_EscapeMap. /be

js> function f() { "use strict"; return "\u00007" } js> print(f); function f() { "use strict"; return "\x007"; } js> print(eval(uneval(f))); undefined

Comment 4 demonstrates correct behavior. Recall that eval returns the result of evaluating a Program, not an Expression, and a function statement doesn't affect completion value, so |undefined| gets returned. This got fixed by bug 430927.

Complete demo of the correct behavior (modulo bug 706305) : js> function f() { "use strict"; return "\u00007" } js> print(f); function f() { "use strict"; return "\x007"; } js> print(eval( ("(" + uneval(f) + ")" ))) function f() { "use strict"; return "\x007"; }