From 84e8a07065543be09fd41ed594c80760c527f2d6 Mon Sep 17 00:00:00 2001 From: Josh Taylor Date: Fri, 29 Aug 2008 18:06:34 -0700 Subject: [PATCH] Fixed bug in StringUtil::vform(). StringUtil::vform() formats a variable argument vector into a std::string. It tries to use vsnprintf into a 1024 character buffer. If that fails because the buffer is too small, it grows the buffer and tries again. However, it was reusing the same va_list argument pointer, which points off the end of the argument list after the first go-around with vsnprintf. The second try usually crashes, or at least results in something unexpected. Fixed this by saving the va_list state using va_copy(). This is a C99 macro, so older systems might have a problem with this fix. --- src/StringUtil.cpp | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-) diff --git a/src/StringUtil.cpp b/src/StringUtil.cpp index e30890a..6b050a3 100644 --- a/src/StringUtil.cpp +++ b/src/StringUtil.cpp @@ -39,7 +39,12 @@ namespace log4cpp { char* buffer = new char[size]; while (1) { - int n = VSNPRINTF(buffer, size, format, args); + va_list args_copy; + va_copy(args_copy, args); + + int n = VSNPRINTF(buffer, size, format, args_copy); + + va_end(args_copy); // If that worked, return a string. if ((n > -1) && (static_cast(n) < size)) { -- 1.5.6.GIT