corrections for octal escape sequences; allows "\0" alone; see jashke…

…nas#1547

Relevant sections of the spec:
* http://es5.github.com/#C
* http://es5.github.com/#B.1.2
* http://es5.github.com/#x7.8.4

src/lexer.coffee

@@ -164,7 +164,7 @@ exports.Lexer = class Lexer
           @token 'STRING', @escapeLines string
       else
         return 0
-    if octalEsc = /^(?:\\.|[^\\])*\\[0-7]/.test string
+    if octalEsc = /^(?:\\.|[^\\])*\\(?:0[0-7]|[1-7])/.test string
       @error "octal escape sequences #{string} are not allowed"
     @line += count string, '\n'
     string.length

test/strict.coffee

@@ -18,9 +18,9 @@
 
 # helper to assert that code complies with strict prohibitions
 strict = (code, msg) ->
-  throws (-> CoffeeScript.compile code), null, msg
+  throws (-> CoffeeScript.compile code), null, msg ? code
 strictOk = (code, msg) ->
-  doesNotThrow (-> CoffeeScript.compile code), msg
+  doesNotThrow (-> CoffeeScript.compile code), msg ? code
 
 
 test "octal integer literals prohibited", ->
@@ -32,19 +32,28 @@ test "octal integer literals prohibited", ->
   strictOk  '`01`'
 
 test "octal escape sequences prohibited", ->
-  strict    '"\\0"'
+  strict    '"\\1"'
   strict    '"\\7"'
-  strict    '"\\000"'
+  strict    '"\\001"'
   strict    '"\\777"'
-  strict    '"_\\0"'
-  strict    '"\\0_"'
-  strict    '"_\\0_"'
-  strict    '"\\08"'
-  strict    '"\\\\\\0"'
+  strict    '"_\\1"'
+  strict    '"\\1_"'
+  strict    '"_\\1_"'
+  strict    '"\\\\\\1"'
+  strictOk  '"\\0"'
+  eq "\x00", "\0"
+  strictOk  '"\\08"'
+  eq "\x008", "\08"
+  strictOk  '"\\0\\8"'
+  eq "\x008", "\0\8"
   strictOk  '"\\8"'
-  strictOk  '"\\\\0"'
-  strictOk  '"\\\\\\\\0"'
-  strictOk  "`'\\0'`"
+  eq "8", "\8"
+  strictOk  '"\\\\1"'
+  eq "\\" + "1", "\\1"
+  strictOk  '"\\\\\\\\1"'
+  eq "\\\\" + "1", "\\\\1"
+  strictOk  "`'\\1'`"
+  eq "\\" + "1", `"\\1"`
 
 
 test "duplicate property definitions in object literals are prohibited", ->