RFR: 6522873 - Java not print "Unrecognized option" when it is invalid option.

[Jesper Wilhelmsson]

Hi,

Please review this patch to make argument parsing stop accepting random 
characters at the end of command line flags. This topic was discussed in 
hotspot-dev at openjdk.java.net and I strongly believe that this bug should be 
reopened and fixed.

Short summary of the problem:
Today some (not all) flags are accepted even though they have random characters 
appended to them. Some examples are -Xconcgc, -Xcomp, -Xboundthreads, 
-XX:+AlwaysTenure etc which will also be accepted when written for instance 
-Xconcgcnoway, -Xcomposer, -Xboundthreadstodogs or -XX:+AlwaysTenureAtBlueMoon

There is a potential problem here since we will also accept things like 
-XX:+ExtendedDTraceProbes-XX:+UseG1GC without saying a word (and of course 
without running with G1).

Bug: https://bugs.openjdk.java.net/browse/JDK-6522873
Webrev: http://cr.openjdk.java.net/~jwilhelm/6522873/webrev.00/


The full list of flags affected by this change is:

-Xnoclassgc
-Xconcgc
-Xnoconcgc
-Xbatch
-green
-native
-Xsqnopause
-Xrs
-Xusealtsigs
-Xoptimize
-Xprof
-Xconcurrentio
-Xinternalversion
-Xprintflags
-Xint
-Xmixed
-Xcomp
-Xshare:dump
-Xshare:on
-Xshare:auto
-Xshare:off
-Xdebug
-Xnoagent
-Xboundthreads
vfprintf
exit
abort
-XX:+AggressiveHeap
-XX:+NeverTenure
-XX:+AlwaysTenure
-XX:+CMSPermGenSweepingEnabled
-XX:-CMSPermGenSweepingEnabled
-XX:+UseGCTimeLimit
-XX:-UseGCTimeLimit
-XX:+ResizeTLE
-XX:-ResizeTLE
-XX:+PrintTLE
-XX:-PrintTLE
-XX:+UseTLE
-XX:-UseTLE
-XX:+DisplayVMOutputToStderr
-XX:+DisplayVMOutputToStdout
-XX:+ExtendedDTraceProbes
-XX:+FullGCALot
-XX:+ManagementServer
-XX:+PrintVMOptions
-XX:-PrintVMOptions
-XX:+IgnoreUnrecognizedVMOptions
-XX:-IgnoreUnrecognizedVMOptions
-XX:+PrintFlagsInitial
-XX:+PrintFlagsWithComments


Thanks,
/Jesper