Seg fault on internal output to a character scalar coarray

[Damian Rouson]

I just submitted the example below as PR 57093.  This code seg faults with gfortran 4.7, 4.8, and 4.9.  With the Cray compiler, it compiles and runs without error. 

$ cat co_hello.f90 
program main 
 ! len<25 produces the expected result len>=25 seg faults 
  character(len=25), allocatable :: greeting[:] 
  allocate(greeting[*])
  write(greeting,"(a)") "z"
end 

$ gfortran -fcoarray=single co_hello.f90 

$ ./a.out
a.out(35951) malloc: *** error for object 0x7fc5ba404c20: pointer being freed
was not allocated
*** set a breakpoint in malloc_error_break to debug

Program received signal SIGABRT: Process abort signal.

Backtrace for this error:
#0  0x1055d2e62
#1  0x1055d362e
#2  0x7fff90ae6949
Abort trap: 6

$ gfortran --version
GNU Fortran (MacPorts gcc49 4.9-20130414_0) 4.9.0 20130414 (experimental)