When running make menuconfig from /wr/etc, mconf was crashing when dialog box
in the style of radiolist was displayed and special keys (like arrow keys)
were pressed. Crash was due to assetion in function toupper from uClibc.
Function to upper should return unchanged value if passed parameter is not
alpha. However, uClibc's implementation behaves in the different way,
it asserts.
After assert following message was printed:
(./mconf: libc/misc/ctype/ctype.c: 320: toupper:
Assertion `((((unsigned int)((c) - 0)) <= ((127 * 2 + 1) - 0)) ||
((c) == (-1)))' failed.
Signed-off-by: Adam Wujek <adam.wujek@cern.ch>