realpath when given file with ending '/'

[EvenOAndersen]

When doing:

fclose(fopen("**/tmp/file.txt**", "wt"));

char *rpr = realpath("**/tmp/file.txt/**",  ....)

The result is "/tmp/file.txt"

Is this correct ?

[sbc100]

I tried running the above code and it failed because fopen fails (because **/tmp directory doesn't exist)..

However I modified that above example to use /tmp instead and it seemed to behave correctly:

$ cat test.c
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>

int main() {
  FILE* f = fopen("/tmp/file.txt**", "wt");
  printf("%p\n", f);
  if (!f) return 0;
  fclose(f);
  char *rpr = realpath("/tmp/file.txt/**",  NULL);
  printf("rpr: %s\n", rpr);
  return 0;
}
$ emcc test.c
$ node ./a.out.js 
0x11278
rpr: (null)

Could you share full failing example perhaps?

[EvenOAndersen]

Sorry about that. The '*' was added when I made the filename bold.
The problem, is a filename with a single ending '/' (no stars) like this:

include <stdio.h>
#include <stdlib.h>
#include <limits.h>

int main() {
  FILE* f = fopen("/tmp/file.txt", "wt");
  printf("%p\n", f);
  if (!f) return 0;
  fclose(f);
  char *rpr = realpath("/tmp/file.txt/",  NULL);
  printf("rpr: %s\n", rpr);
  return 0;
}

[EvenOAndersen]

and the expected result is nullptr

[sbc100]

@hoodmane, this looks like the kind of issue you have been working on recently. Do you know if you have any outstanding changes here that might fix this?

[hoodmane]

Right, I still reproduce it on tip of tree. I will see if I can fix it.

[sbc100]

Looks like I had a PR back in august: #22352. Not sure if its worth keeping/resurrecting.

[Sainul007]

Ok, alright