[CMake] Problem with FindBISON.cmake in Spanish language

[Karl Krissian]

Hi,

In a Spanish language (linux), the command bison --version outputs:
bison (GNU bison) 2.4.1 etc...

while in an English language, the command bison --version outputs:
bison (GNU Bison) 2.4.1 etc...

the difference is the uppercase or lowercase b in GNU bison.
This difference creates a problem in FindBISON.cmake for the variable 
BISON_VERSION, which relies on the English output:

  EXECUTE_PROCESS(COMMAND ${BISON_EXECUTABLE} --version
     OUTPUT_VARIABLE BISON_version_output
     ERROR_VARIABLE BISON_version_error
     RESULT_VARIABLE BISON_version_result
     OUTPUT_STRIP_TRAILING_WHITESPACE)
   IF(NOT ${BISON_version_result} EQUAL 0)
     MESSAGE(SEND_ERROR "Command \"${BISON_EXECUTABLE} --version\" 
failed with ou
tput:\n${BISON_version_error}")
   ELSE()
     STRING(REGEX REPLACE "^bison \\(GNU Bison\\) ([^\n]+)\n.*" "\\1"
       BISON_VERSION "${BISON_version_output}")
   ENDIF()


and with the nightly build of cmake, the variable BISON_VERSION appears 
in CMakeCache.txt and, in Spanish, generates an error since it contains 
the full ouput of the command "bison --version" instead of only the 
version number.
There are many ways to fix it, by changing the regular expression in the 
REPLACE command, one way is to write
     STRING(REGEX REPLACE "^bison \\(GNU [Bb]ison\\) ([^\n]+)\n.*" "\\1"
       BISON_VERSION "${BISON_version_output}")


Hope it can help for the next release,

Regards,

Karl Krissian