From 406562ac6d3863dfdaedbf40f9d4a23ca37c9ec5 Mon Sep 17 00:00:00 2001
From: ZyX <kp-pav@yandex.ru>
Date: Sun, 21 Feb 2016 21:33:58 +0300
Subject: encode: Fail to dump NaN and infinity

Thanks to vim/vim#654
---
 src/nvim/eval/encode.c                       | 21 ++++++++++++++++++---
 test/functional/eval/json_functions_spec.lua |  9 +++++++++
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/src/nvim/eval/encode.c b/src/nvim/eval/encode.c
index a131f5c3c1..d21347cca6 100644
--- a/src/nvim/eval/encode.c
+++ b/src/nvim/eval/encode.c
@@ -7,6 +7,7 @@
 #include <msgpack.h>
 #include <inttypes.h>
 #include <assert.h>
+#include <math.h>
 
 #include "nvim/eval/encode.h"
 #include "nvim/buffer_defs.h"  // vimconv_T
@@ -827,9 +828,23 @@ DEFINE_VIML_CONV_FUNCTIONS(, echo, garray_T *const, gap)
 #undef CONV_FLOAT
 #define CONV_FLOAT(flt) \
     do { \
-      char numbuf[NUMBUFLEN]; \
-      vim_snprintf(numbuf, NUMBUFLEN - 1, "%g", (flt)); \
-      ga_concat(gap, numbuf); \
+      const float_T flt_ = (flt); \
+      switch (fpclassify(flt_)) { \
+        case FP_NAN: { \
+          EMSG(_("E474: Unable to represent NaN value in JSON")); \
+          return FAIL; \
+        } \
+        case FP_INFINITE: { \
+          EMSG(_("E474: Unable to represent infinity in JSON")); \
+          return FAIL; \
+        } \
+        default: { \
+          char numbuf[NUMBUFLEN]; \
+          vim_snprintf(numbuf, NUMBUFLEN - 1, "%g", flt_); \
+          ga_concat(gap, (char_u *) numbuf); \
+          break; \
+        } \
+      } \
     } while (0)
 
 /// Last used p_enc value
diff --git a/test/functional/eval/json_functions_spec.lua b/test/functional/eval/json_functions_spec.lua
index 0b0403ce8e..33d177a2b6 100644
--- a/test/functional/eval/json_functions_spec.lua
+++ b/test/functional/eval/json_functions_spec.lua
@@ -472,6 +472,15 @@ describe('json_encode() function', function()
     eq('1.0e50', eval('json_encode(1.0e50)'))
   end)
 
+  it('fails to dump NaN and infinite values', function()
+    eq('Vim(call):E474: Unable to represent NaN value in JSON',
+       exc_exec('call json_encode(str2float("nan"))'))
+    eq('Vim(call):E474: Unable to represent infinity in JSON',
+       exc_exec('call json_encode(str2float("inf"))'))
+    eq('Vim(call):E474: Unable to represent infinity in JSON',
+       exc_exec('call json_encode(-str2float("inf"))'))
+  end)
+
   it('dumps lists', function()
     eq('[]', funcs.json_encode({}))
     eq('[[]]', funcs.json_encode({{}}))
-- 
cgit