https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109358
Bug ID: 109358 Summary: Wrong formatting with T-descriptor during stream output Product: gcc Version: 12.2.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: fortran Assignee: unassigned at gcc dot gnu.org Reporter: baradi09 at gmail dot com Target Milestone: --- This is a very minor bug, but probably easy to fix. It seems, that the T data edit descriptor handling is non-standard conforming when using formatted stream I/O: Given the following MWE: program tabformat implicit none integer :: fd open(newunit=fd, file="test.stream.txt", access="stream", form="formatted") write(fd, "(a)") "1234567890123" write(fd, "(a, t10, a)") "1234", "0123" ! A-descriptor, file positioning allowed write(fd, "(i4, t10, i4.4)") 1234, 0123 ! I-descriptor, file positioning not allowed close(fd) end program tabformat The resulting file contains 1234567890123 1234 0123 # 9 spaces between blocks 1234 0123 # 9 spaces between blocks Apparently, a file positioning takes place during the execution of the write statement. However, if I understand 13.7.1 ยง1 correctly, file positioning may only happen with the A-descriptor (and it is optional even there). So the standard conforming output would be either (if file positioning happens after the A-descriptor) 1234567890123 1234 0123 # 9 spaces 1234 0123 # 5 spaces or (if no file positioning happens after the A-descriptor) 1234567890123 1234 0123 # 5 spaces 1234 0123 # 5 spaces I personally would prefer latter, and it would be also equivalent to the behavior of the Intel and NAG compilers.