From 3b092bd9b6b3953d5c3052d57e4827dbd85941fd Mon Sep 17 00:00:00 2001
From: "Wladimir J. van der Laan" <laanwj@gmail.com>
Date: Thu, 9 Mar 2017 10:37:45 +0000
Subject: [PATCH 1/2] util: Properly handle errors during log message
 formatting

Instead of having an exception propagate into the program when an
error happens while formatting a log message, just print a message to
the log.

Addresses #9423.
---
 src/util.h | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/src/util.h b/src/util.h
index e27ce121c..c9d465954 100644
--- a/src/util.h
+++ b/src/util.h
@@ -73,14 +73,24 @@ bool LogAcceptCategory(const char* category);
 /** Send a string to the log output */
 int LogPrintStr(const std::string &str);
 
-#define LogPrint(category, ...) do { \
-    if (LogAcceptCategory((category))) { \
-        LogPrintStr(tfm::format(__VA_ARGS__)); \
-    } \
-} while(0)
+/** Get format string from VA_ARGS for error reporting */
+template<typename... Args> std::string FormatStringFromLogArgs(const char *fmt, const Args&... args) { return fmt; }
 
 #define LogPrintf(...) do { \
-    LogPrintStr(tfm::format(__VA_ARGS__)); \
+    std::string _log_msg_; /* Unlikely name to avoid shadowing variables */ \
+    try { \
+        _log_msg_ = tfm::format(__VA_ARGS__); \
+    } catch (std::runtime_error &e) { \
+        /* Original format string will have newline so don't add one here */ \
+        _log_msg_ = "Error \"" + std::string(e.what()) + "\" while formatting log message: " + FormatStringFromLogArgs(__VA_ARGS__); \
+    } \
+    LogPrintStr(_log_msg_); \
+} while(0)
+
+#define LogPrint(category, ...) do { \
+    if (LogAcceptCategory((category))) { \
+        LogPrintf(__VA_ARGS__); \
+    } \
 } while(0)
 
 template<typename... Args>

From b651270cd6bfdd6d7c4acf04d1a00c03bf09f03a Mon Sep 17 00:00:00 2001
From: "Wladimir J. van der Laan" <laanwj@gmail.com>
Date: Mon, 13 Mar 2017 06:51:15 +0100
Subject: [PATCH 2/2] util: Throw tinyformat::format_error on formatting error

Throw tinyformat::format_error on formatting error instead of the
`std::runtime_error`.
---
 src/tinyformat.h | 9 ++++++++-
 src/util.h       | 2 +-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/tinyformat.h b/src/tinyformat.h
index 17f0360c4..5022d4680 100644
--- a/src/tinyformat.h
+++ b/src/tinyformat.h
@@ -123,7 +123,7 @@ namespace tinyformat {}
 namespace tfm = tinyformat;
 
 // Error handling; calls assert() by default.
-#define TINYFORMAT_ERROR(reasonString) throw std::runtime_error(reasonString)
+#define TINYFORMAT_ERROR(reasonString) throw tinyformat::format_error(reasonString)
 
 // Define for C++11 variadic templates which make the code shorter & more
 // general.  If you don't define this, C++11 support is autodetected below.
@@ -164,6 +164,13 @@ namespace tfm = tinyformat;
 
 namespace tinyformat {
 
+class format_error: public std::runtime_error
+{
+public:
+    format_error(const std::string &what): std::runtime_error(what) {
+    }
+};
+
 //------------------------------------------------------------------------------
 namespace detail {
 
diff --git a/src/util.h b/src/util.h
index c9d465954..87eb16c91 100644
--- a/src/util.h
+++ b/src/util.h
@@ -80,7 +80,7 @@ template<typename... Args> std::string FormatStringFromLogArgs(const char *fmt,
     std::string _log_msg_; /* Unlikely name to avoid shadowing variables */ \
     try { \
         _log_msg_ = tfm::format(__VA_ARGS__); \
-    } catch (std::runtime_error &e) { \
+    } catch (tinyformat::format_error &e) { \
         /* Original format string will have newline so don't add one here */ \
         _log_msg_ = "Error \"" + std::string(e.what()) + "\" while formatting log message: " + FormatStringFromLogArgs(__VA_ARGS__); \
     } \