Bob Seque / mbed-dev

mbed library sources. Supersedes mbed-src.

Fork of mbed-dev by mbed official

Diff: common/RawSerial.cpp

Revision:
47:e32b5dd8af6d
Parent:
0:9b334a45a8ff
--- a/common/RawSerial.cpp	Mon Jan 11 09:45:10 2016 +0000
+++ b/common/RawSerial.cpp	Mon Jan 11 17:00:10 2016 +0000
@@ -47,7 +47,10 @@
 int RawSerial::printf(const char *format, ...) {
     std::va_list arg;
     va_start(arg, format);
-    int len = vsnprintf(NULL, 0, format, arg);
+    // ARMCC microlib does not properly handle a size of 0.
+    // As a workaround supply a dummy buffer with a size of 1.
+    char dummy_buf[1];
+    int len = vsnprintf(dummy_buf, sizeof(dummy_buf), format, arg);
     if (len < STRING_STACK_LIMIT) {
         char temp[STRING_STACK_LIMIT];
         vsprintf(temp, format, arg);