From 6d079554a634d6d9a80ad83624a8487a2b4202dd Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Tue, 6 Dec 2016 13:37:54 +1100
Subject: [PATCH] format: fix escaped percent before value specifier

---
 format.ipp      | 6 +++++-
 test/format.cpp | 2 ++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/format.ipp b/format.ipp
index e1a69d3f..92721b40 100644
--- a/format.ipp
+++ b/format.ipp
@@ -897,7 +897,11 @@ namespace util { namespace format { namespace detail {
 
         specifier spec;
         auto cursor = parse (start, last, spec);
-        return _render (write (os, spec, val), cursor, last, args...);
+
+        if (spec.k == specifier::kind::ESCAPE)
+            return _render (write (os, spec     ), cursor, last, val, args...);
+        else
+            return _render (write (os, spec, val), cursor, last,      args...);
     }
 
 
diff --git a/test/format.cpp b/test/format.cpp
index 2d8fe76d..ca4efa5a 100644
--- a/test/format.cpp
+++ b/test/format.cpp
@@ -162,6 +162,8 @@ main (void)
     CHECK_RENDER ("%% %%", "% %");
     CHECK_RENDER (" %% %% ", " % % ");
 
+    CHECK_RENDER ("%%%d%%", "%0%", 0);
+
     CHECK_RENDER ("%u %u", "1 2", 1u, 2u);
 
     CHECK_RENDER ("%#o %o", "010 10", 8u, 8u);