POSIX shells treat an unquoted [abcd] as a pattern bracket expression
and apply it for filename expansion. This kicks in and causes
troubles in the space_pad_to function when it's called to pad prefix
tags like '[AUTODETECT]', because the argument holding such a tag is
passed to a shell unquoted. The result is funny output when the
directory containing the Makefile also contains any files or
directories, whose name is a single upper-case character that can be
found in any prefix tags:
$ touch A B C D
$ make
-------------------------
Arduino.mk Configuration:
- A C D CURRENT_OS = LINUX
- [USER] ARDUINO_DIR = /home/szeder/src/arduino/arduino-1.8.1
- [USER] ARDMK_DIR = /home/szeder/src/arduino/Arduino-Makefile
- A C D ARDUINO_VERSION = 181
- A D ARCHITECTURE = avr
- A D ARDMK_VENDOR = arduino
- A D ARDUINO_SKETCHBOOK =
<snip>
Prevent this by quoting space_pad_to's parameter when passing it to a
shell.
