Bug 77360 - Self-assignment of allocatable character array yields erroneous result

[Damian Rouson]

Gfortran developers,

As demonstrated below, the assignment of an allocatable character array element to itself leads to an erroneous result with gfortran 6.1.0. The same code yields the correct output ('a') with gfortran 5.4.0 and 7.0.0. Dead code plays a role: the "if (.false.)" statement is required to demonstrate the problem.

Damian 

$ cat self-assign-char-array.f90 
character(1), allocatable :: linelist(:) 
linelist = ['a'] 
if (.false.) linelist(1) = linelist(1) 
linelist(1) = linelist(1) 
print *,linelist(1) 
end 
$ gfortran self-assign-char-array.f90 
$ ./a.out 

$ gfortran —version 
GNU Fortran (MacPorts gcc6 6.1.0_0) 6.1.0