Shared/Logs: Fix crash in Console log output

Correctly handle the return value of vsnprintf() which returns -1 if the buffer is too small http://msdn.microsoft.com/en-us/library/1kt27hek.aspx . In this case just truncate the output.
This caused a crash on character delete if Logger.entities.player.dump was enabled and set to 3.
Fixes #11539

1 files changed, 3 insertions, 0 deletions

diff --git a/src/server/shared/Utilities/Util.cpp b/src/server/shared/Utilities/Util.cpp
index 499ad0502b7..ffef61557fc 100644
--- a/src/server/shared/Utilities/Util.cpp
+++ b/src/server/shared/Utilities/Util.cpp
@@ -510,6 +510,9 @@ void vutf8printf(FILE* out, const char *str, va_list* ap)
     wchar_t wtemp_buf[32*1024];
 
     size_t temp_len = vsnprintf(temp_buf, 32*1024, str, *ap);
+    //vsnprintf returns -1 if the buffer is too small
+    if (temp_len == size_t(-1))
+        temp_len = 32*1024-1;
 
     size_t wtemp_len = 32*1024-1;
     Utf8toWStr(temp_buf, temp_len, wtemp_buf, wtemp_len);