From 4bb41d065bb0474582042462cf9c34bdbc1e50e3 Mon Sep 17 00:00:00 2001
From: Niels Lohmann <niels.lohmann@gmail.com>
Date: Wed, 23 Nov 2016 16:57:01 +0100
Subject: [PATCH] :bug: parsing erroneous files yields an exception (#366)

---
 src/json.hpp                 | 6 ++++++
 src/json.hpp.re2c            | 6 ++++++
 test/src/unit-regression.cpp | 6 ++++++
 3 files changed, 18 insertions(+)

diff --git a/src/json.hpp b/src/json.hpp
index e71ffc4a2..dbe49c2a2 100644
--- a/src/json.hpp
+++ b/src/json.hpp
@@ -7597,6 +7597,12 @@ class basic_json
         explicit lexer(std::istream& s)
             : m_stream(&s), m_line_buffer()
         {
+            // immediately abort if stream is erroneous
+            if (s.fail())
+            {
+                throw std::invalid_argument("stream error: " +  std::string(strerror(errno)));
+            }
+
             // fill buffer
             fill_line_buffer();
 
diff --git a/src/json.hpp.re2c b/src/json.hpp.re2c
index 9eccc144f..ef9910ce2 100644
--- a/src/json.hpp.re2c
+++ b/src/json.hpp.re2c
@@ -7597,6 +7597,12 @@ class basic_json
         explicit lexer(std::istream& s)
             : m_stream(&s), m_line_buffer()
         {
+            // immediately abort if stream is erroneous
+            if (s.fail())
+            {
+                throw std::invalid_argument("stream error: " +  std::string(strerror(errno)));
+            }
+
             // fill buffer
             fill_line_buffer();
 
diff --git a/test/src/unit-regression.cpp b/test/src/unit-regression.cpp
index 661edc25f..ac6d25df1 100644
--- a/test/src/unit-regression.cpp
+++ b/test/src/unit-regression.cpp
@@ -495,4 +495,10 @@ TEST_CASE("regression tests")
         json j = json::parse("22e2222");
         CHECK(j == json());
     }
+
+    SECTION("issue #366 - json::parse on failed stream gets stuck")
+    {
+        std::ifstream f("file_not_found.json");
+        CHECK_THROWS_AS(json::parse(f), std::invalid_argument);
+    }
 }