since we have installed the new version of perforceSCM(1.3.26) we get the following error from perforce if we call p4 from shell-plugin:
[we found a bug/bugfix for the bug jenkins-9906. it is the same bug? ]

Slashes ( // ) not allowed in matrixjob/branch=work-lable=matrix--changelistnumber.

If the p4 ($P4CLIENT is correct) is called from perforceSCM itself, everything looks okay.
You can see it in the logs like:

#/usr/bin/p4 -P ABCDEFG12345 -s sync -f matrixjob-branch-work-lable-matrix--changelistnumber

Once perforce is called from shell, the job name($P4CLIENT ) has invalid characters (in this case / ).

this is the perforce command
#/usr/bin/p4 diff -sa

and we get the following error
"Slashes ( // ) not allowed in matrixjob/branch=work,lable=matrix--changelistnumber."

and the job name has invalid characters (in this case '/' ',' '=' )

it is a bug in perforceSCM or in shell-plugin?