From b22b4ca9356e28e2d3e3486830df08260ad11a1f Mon Sep 17 00:00:00 2001
From: jkriege2 <jan@jkrieger.de>
Date: Sat, 27 Jun 2020 14:35:45 +0200
Subject: [PATCH] Fixed Bug #43: jkqtp_format() had undefined behaviour,
 because va_start was called with a ref-parameter, which does not work. Now
 there are 4 overloaded template variants. See
 https://github.com/jkriege2/JKQtPlotter/issues/43

---
 lib/jkqtcommon/jkqtpstringtools.cpp | 11 +--------
 lib/jkqtcommon/jkqtpstringtools.h   | 37 ++++++++++++++++++++++++++++-
 2 files changed, 37 insertions(+), 11 deletions(-)

diff --git a/lib/jkqtcommon/jkqtpstringtools.cpp b/lib/jkqtcommon/jkqtpstringtools.cpp
index f6f59a15f4..029f4ba71a 100644
--- a/lib/jkqtcommon/jkqtpstringtools.cpp
+++ b/lib/jkqtcommon/jkqtpstringtools.cpp
@@ -81,19 +81,10 @@ std::string jkqtp_tolower(const std::string& s){
   return d;
 };
 
- std::string jkqtp_format(const std::string& templ, ...){
-  va_list ap;
-  char buffer[4096];
-  va_start (ap, templ);
-  vsnprintf(buffer, 4096, templ.c_str(), ap);
-  va_end (ap);
-  std::string ret(buffer);
-  return ret;
-};
 
 
  std::string jkqtp_bytestostr(double bytes){
-    double data=bytes;
+  double data=bytes;
   std::string form="%.0lf";
   std::string res=jkqtp_format(form,data);
   form="%.3lf";
diff --git a/lib/jkqtcommon/jkqtpstringtools.h b/lib/jkqtcommon/jkqtpstringtools.h
index 3c8a5cec2c..0910a204f1 100644
--- a/lib/jkqtcommon/jkqtpstringtools.h
+++ b/lib/jkqtcommon/jkqtpstringtools.h
@@ -89,7 +89,42 @@ JKQTCOMMON_LIB_EXPORT std::string jkqtp_toupper(const std::string& s);
 /** \brief std::string wrapper around sprintf()
  * \ingroup jkqtptools_string
  */
-JKQTCOMMON_LIB_EXPORT std::string jkqtp_format(const std::string& templ, ...);
+template <class T1>
+inline std::string jkqtp_format(const std::string& templ, T1 d1) {
+    char buffer[4096];
+    snprintf(buffer, 4096, templ.c_str(), d1);
+    return std::string(buffer);
+};
+
+/** \brief std::string wrapper around sprintf()
+ * \ingroup jkqtptools_string
+ */
+template <class T1, class T2>
+inline std::string jkqtp_format(const std::string& templ, T1 d1, T2 d2) {
+    char buffer[4096];
+    snprintf(buffer, 4096, templ.c_str(), d1, d2);
+    return std::string(buffer);
+};
+
+/** \brief std::string wrapper around sprintf()
+ * \ingroup jkqtptools_string
+ */
+template <class T1, class T2, class T3>
+inline std::string jkqtp_format(const std::string& templ, T1 d1, T2 d2, T3 d3) {
+    char buffer[4096];
+    snprintf(buffer, 4096, templ.c_str(), d1, d2, d3);
+    return std::string(buffer);
+};
+
+/** \brief std::string wrapper around sprintf()
+ * \ingroup jkqtptools_string
+ */
+template <class T1, class T2, class T3, class T4>
+inline std::string jkqtp_format(const std::string& templ, T1 d1, T2 d2, T3 d3, T4 d4) {
+    char buffer[4096];
+    snprintf(buffer, 4096, templ.c_str(), d1, d2, d3, d4);
+    return std::string(buffer);
+};
 
 /** \brief convert a number of bytes to a string, formatting e.g. 1024 as 1kB, ...
  * \ingroup jkqtptools_string