Improve testing comments and code of issue 2985 (symlink in pyargs).
Improve testing comments and code of issue 2985 (symlink in pyargs).

tomviner/pytest,tomviner/pytest,pytest-dev/pytest,hackebrot/pytest,tareqalayan/pytest,alfredodeza/pytest,nicoddemus/pytest,nicoddemus/pytest,Akasurde/pytest,The-Compiler/pytest,ddboline/pytest,txomon/pytest,The-Compiler/pytest,pfctdayelise/pytest,RonnyPfannschmidt/pytest,markshao/pytest,davidszotten/pytest