Set $SHELL in tests that use shell/2

The `shell/2` predicate always runs its argument in the user's
donfigured shell. This is not always POSIX compliant, because some
people use stuff like fish and Nushell. This sets the $SHELL env var
to /bin/sh, which is a POSIX compliant shell in any reasonable Unix.

Author: bakaq

tests-pl/issue_delete_directory.pl

@@ -21,7 +21,8 @@
 
 main :-
     call_cleanup(
-       (setenv("TARGET_DIRECTORY", "delete_directory_test"),
+       (setenv("SHELL", "/bin/sh"),
+        setenv("TARGET_DIRECTORY", "delete_directory_test"),
         shell("mkdir delete_directory_test", 0),
         check),
         shell("test -d delete_directory_test && rmdir delete_directory_test || true", 0)

tests-pl/issue_delete_file.pl

@@ -21,7 +21,8 @@
 
 main :-
     call_cleanup(
-       (setenv("TARGET_FILE", "delete_file_test"),
+       (setenv("SHELL", "/bin/sh"),
+        setenv("TARGET_FILE", "delete_file_test"),
         shell("touch delete_file_test", 0),
         check),
         shell("test -e delete_file_test && rm delete_file_test || true", 0)

tests-pl/issue_directory_files.pl

@@ -16,7 +16,8 @@
 main :-
     path_segments(Path, ["directory_files_test_parent", "directory_files_test_file"]),
     call_cleanup(
-       (setenv("TARGET_DIRECTORY", "directory_files_test_parent"),
+       (setenv("SHELL", "/bin/sh"),
+        setenv("TARGET_DIRECTORY", "directory_files_test_parent"),
         shell("test -d directory_files_test_parent || mkdir directory_files_test_parent", 0),
         append(["test -e ", Path, " || touch ", Path], Cmd),
         shell(Cmd, 0),

tests-pl/issue_file_copy.pl

@@ -26,7 +26,8 @@
 
 main :-
     call_cleanup(
-       (setenv("SOURCE", "file_copy_test_source"),
+       (setenv("SHELL", "/bin/sh"),
+        setenv("SOURCE", "file_copy_test_source"),
         setenv("DESTINATION", "file_copy_test_destination"),
         shell("touch file_copy_test_source", 0),
         check),

tests-pl/issue_file_exists.pl

@@ -16,7 +16,8 @@
 
 main :-
     call_cleanup(
-       (setenv("TARGET_FILE", "file_exists_test"),
+       (setenv("SHELL", "/bin/sh"),
+        setenv("TARGET_FILE", "file_exists_test"),
         shell("touch file_exists_test", 0),
         check),
         shell("rm -f file_exists_test", 0)

tests-pl/issue_file_size.pl

@@ -14,7 +14,8 @@
 
 main :-
     call_cleanup(
-       (setenv("TARGET_FILE", "file_size_test"),
+       (setenv("SHELL", "/bin/sh"),
+        setenv("TARGET_FILE", "file_size_test"),
         shell("echo '1' > file_size_test", 0),
         check),
         shell("rm -f file_size_test", 0)

tests-pl/issue_file_time.pl

@@ -16,7 +16,8 @@
 
 main :-
     call_cleanup(
-       (setenv("TARGET_FILE", "file_time_test"),
+       (setenv("SHELL", "/bin/sh"),
+        setenv("TARGET_FILE", "file_time_test"),
         shell("touch file_time_test", 0),
         findall(T, check(T), Ts),
         length(Ts, 3)),

tests-pl/issue_make_directory.pl

@@ -21,7 +21,8 @@
 
 main :-
     call_cleanup(
-       (setenv("TARGET_DIRECTORY", "make_directory_test"),
+       (setenv("SHELL", "/bin/sh"),
+        setenv("TARGET_DIRECTORY", "make_directory_test"),
         check),
         shell("test -d make_directory_test && rmdir make_directory_test || true", 0)
     ).

tests-pl/issue_make_directory_path.pl

@@ -21,7 +21,8 @@
 
 main :-
     call_cleanup(
-       (setenv("TARGET_DIRECTORY", "make_directory_test/subdir"),
+       (setenv("SHELL", "/bin/sh"),
+        setenv("TARGET_DIRECTORY", "make_directory_test/subdir"),
         check),
        (shell("test -d make_directory_test/subdir && rmdir make_directory_test/subdir || true", 0),
         shell("test -d make_directory_test && rmdir make_directory_test || true", 0))

tests-pl/issue_path_canonical.pl

@@ -18,7 +18,8 @@
 main :-
     path_segments(Path, ["path_canonical_test", "..", "path_canonical_test"]),
     call_cleanup(
-       (setenv("TARGET_PATH", Path),
+       (setenv("SHELL", "/bin/sh"),
+        setenv("TARGET_PATH", Path),
         shell("mkdir path_canonical_test", 0),
         check),
        shell("test -d path_canonical_test && rmdir path_canonical_test || true", 0)