diff -r 000000000000 -r 6474c204b198 xpcom/glue/nsID.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xpcom/glue/nsID.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,116 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsID.h"
+#include "prprf.h"
+#include "nsMemory.h"
+
+/**
+ * Multiplies the_int_var with 16 (0x10) and adds the value of the
+ * hexadecimal digit the_char. If it fails it returns false from
+ * the function it's used in.
+ */
+
+#define ADD_HEX_CHAR_TO_INT_OR_RETURN_FALSE(the_char, the_int_var) \
+    the_int_var = (the_int_var << 4) + the_char; \
+    if(the_char >= '0' && the_char <= '9') the_int_var -= '0'; \
+    else if(the_char >= 'a' && the_char <= 'f') the_int_var -= 'a'-10; \
+    else if(the_char >= 'A' && the_char <= 'F') the_int_var -= 'A'-10; \
+    else return false
+
+
+/**
+ * Parses number_of_chars characters from the char_pointer pointer and
+ * puts the number in the dest_variable. The pointer is moved to point
+ * at the first character after the parsed ones. If it fails it returns
+ * false from the function the macro is used in.
+ */
+
+#define PARSE_CHARS_TO_NUM(char_pointer, dest_variable, number_of_chars) \
+  do { int32_t _i=number_of_chars; \
+  dest_variable = 0; \
+  while(_i) { \
+    ADD_HEX_CHAR_TO_INT_OR_RETURN_FALSE(*char_pointer, dest_variable); \
+    char_pointer++; \
+    _i--; \
+  } } while(0)
+
+
+/**
+ * Parses a hyphen from the char_pointer string. If there is no hyphen there
+ * the function returns false from the function it's used in. The
+ * char_pointer is advanced one step.
+ */
+
+ #define PARSE_HYPHEN(char_pointer)   if(*(char_pointer++) != '-') return false
+
+/*
+ * Turns a {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} string into
+ * an nsID. It can also handle the old format without the { and }.
+ */
+
+bool nsID::Parse(const char *aIDStr)
+{
+  /* Optimized for speed */
+  if(!aIDStr) {
+    return false;
+  }
+
+  bool expectFormat1 = (aIDStr[0] == '{');
+  if(expectFormat1) aIDStr++;
+
+  PARSE_CHARS_TO_NUM(aIDStr, m0, 8);
+  PARSE_HYPHEN(aIDStr);
+  PARSE_CHARS_TO_NUM(aIDStr, m1, 4);
+  PARSE_HYPHEN(aIDStr);
+  PARSE_CHARS_TO_NUM(aIDStr, m2, 4);
+  PARSE_HYPHEN(aIDStr);
+  int i;
+  for(i=0; i<2; i++)
+    PARSE_CHARS_TO_NUM(aIDStr, m3[i], 2);
+  PARSE_HYPHEN(aIDStr);
+  while(i < 8) {
+    PARSE_CHARS_TO_NUM(aIDStr, m3[i], 2);
+    i++;
+  }
+
+  return expectFormat1 ? *aIDStr == '}' : true;
+}
+
+#ifndef XPCOM_GLUE_AVOID_NSPR
+
+static const char gIDFormat[] =
+  "{%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x}";
+
+/*
+ * Returns an allocated string in {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}
+ * format. The string is allocated with NS_Alloc and should be freed by
+ * the caller.
+ */
+
+char *nsID::ToString() const
+{
+  char *res = (char*)NS_Alloc(NSID_LENGTH);
+
+  if (res != nullptr) {
+    PR_snprintf(res, NSID_LENGTH, gIDFormat,
+                m0, (uint32_t) m1, (uint32_t) m2,
+                (uint32_t) m3[0], (uint32_t) m3[1], (uint32_t) m3[2],
+                (uint32_t) m3[3], (uint32_t) m3[4], (uint32_t) m3[5],
+                (uint32_t) m3[6], (uint32_t) m3[7]);
+  }
+  return res;
+}
+
+void nsID::ToProvidedString(char (&dest)[NSID_LENGTH]) const 
+{
+  PR_snprintf(dest, NSID_LENGTH, gIDFormat,
+              m0, (uint32_t) m1, (uint32_t) m2,
+              (uint32_t) m3[0], (uint32_t) m3[1], (uint32_t) m3[2],
+              (uint32_t) m3[3], (uint32_t) m3[4], (uint32_t) m3[5],
+              (uint32_t) m3[6], (uint32_t) m3[7]);
+}
+
+#endif // XPCOM_GLUE_AVOID_NSPR