Fix recently-introduced file-name-absolute-p typo

Fix a bug introduced in 2019-07-24T21:28:13!eggert@cs.ucla.edu.
* src/fileio.c (file_name_absolute_p):
~/foo is also absolute (Bug#36809).
* test/src/fileio-tests.el (fileio-tests--file-name-absolute-p):
Rename from fileio-tests--no-such-user and add more tests.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/fileio.c b/src/fileio.c
index d1a7f39ac95..968a55e5956 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -2690,7 +2690,8 @@ file_name_absolute_p (char const *filename)
 {
   return (IS_ABSOLUTE_FILE_NAME (filename)
           || (filename[0] == '~'
-              && (!filename[1] || user_homedir (&filename[1]))));
+              && (!filename[1] || IS_DIRECTORY_SEP (filename[1])
+                  || user_homedir (&filename[1]))));
 }
 
 DEFUN ("file-exists-p", Ffile_exists_p, Sfile_exists_p, 1, 1, 0,