2 files changed, 10 insertions, 7 deletions
diff --git a/lib/pure/parseutils.nim b/lib/pure/parseutils.nim
index b3708838a..698bde42a 100644
--- a/lib/pure/parseutils.nim
+++ b/lib/pure/parseutils.nim
@@ -25,7 +25,7 @@ const
 proc toLower(c: char): char {.inline.} =
   result = if c in {'A'..'Z'}: chr(ord(c)-ord('A')+ord('a')) else: c
 
-proc parseHex*(s: string, number: var int, start = 0): int {.
+proc parseHex*(s: string, number: var int, start = 0; maxLen = 0): int {.
   rtl, extern: "npuParseHex", noSideEffect.}  =
   ## Parses a hexadecimal number and stores its value in ``number``.
   ##
@@ -45,11 +45,14 @@ proc parseHex*(s: string, number: var int, start = 0): int {.
   ##   discard parseHex("0x38", value)
   ##   assert value == -200
   ##
+  ## If 'maxLen==0' the length of the hexadecimal number has no
+  ## upper bound. Not more than ```maxLen`` characters are parsed.
   var i = start
   var foundDigit = false
   if s[i] == '0' and (s[i+1] == 'x' or s[i+1] == 'X'): inc(i, 2)
   elif s[i] == '#': inc(i)
-  while true:
+  let last = if maxLen == 0: s.len else: i+maxLen
+  while i < last:
     case s[i]
     of '_': discard
     of '0'..'9':
diff --git a/lib/pure/strutils.nim b/lib/pure/strutils.nim
index aa29bb073..a446f85b4 100644
--- a/lib/pure/strutils.nim
+++ b/lib/pure/strutils.nim
@@ -1210,22 +1210,21 @@ proc unescape*(s: string, prefix = "\"", suffix = "\""): string {.noSideEffect,
   ## If `s` does not begin with ``prefix`` and end with ``suffix`` a
   ## ValueError exception will be raised.
   result = newStringOfCap(s.len)
-  var i = 0
+  var i = prefix.len
   if not s.startsWith(prefix):
     raise newException(ValueError,
                        "String does not start with a prefix of: " & prefix)
-  inc(i)
   while true:
     if i == s.len-suffix.len: break
     case s[i]
     of '\\':
       case s[i+1]:
       of 'x':
-        inc i
+        inc i, 2
         var c: int
-        i += parseutils.parseHex(s, c, i)
+        i += parseutils.parseHex(s, c, i, maxLen=2)
         result.add(chr(c))
-        inc(i, 2)
+        dec i, 2
       of '\\':
         result.add('\\')
       of '\'':
@@ -1721,3 +1720,4 @@ when isMainModule:
   doAssert isUpper("ABC")
   doAssert(not isUpper("AAcc"))
   doAssert(not isUpper("A#$"))
+  doAssert(unescape(r"\x013", "", "") == "\x013")