Make freopen reset the stream orientation.

Signed-off-by: Wren Turkal <wt@penguintechs.org>

src/header/stdio/mod.rs

@@ -519,6 +519,7 @@ pub unsafe extern "C" fn freopen(
         stream.flags = (stream.flags & constants::F_PERM) | new.flags;
         fclose(new);
     }
+    stream.orientation = 0;
     funlockfile(stream);
     stream
 }

tests/expected/stdio/freopen.stdout

@@ -1 +1,3 @@
 Hello
+0
+0

tests/stdio/freopen.c

@@ -1,12 +1,38 @@
+#include <assert.h>
 #include <stdio.h>
+#include <wchar.h>
 
 #include "test_helpers.h"
 
-int main(void) {
+int test_reopen_opens_file(void) {
     FILE *f = freopen("stdio/stdio.in", "r", stdin);
     ERROR_IF(freopen, f, == NULL);
 
     char in[6];
     fgets(in, 6, stdin);
     printf("%s\n", in); // should print Hello
+    fclose(f);
+    return 0;
+}
+
+int test_reopen_resets_orientation(void) {
+    FILE *f = freopen("stdio/stdio.in", "r", stdin);
+    assert(fwide(f, 0) == 0);
+    assert(fwide(f, -1) == -1);
+
+    f = freopen("stdio/stdio.in", "r", stdin);
+    assert(fwide(f, 0) == 0);
+
+    fclose(f);
+    return 0;
+}
+
+int main(void) {
+    int(*tests[])(void) = {
+        &test_reopen_opens_file,
+        &test_reopen_resets_orientation,
+    };
+    for(int i=0; i<sizeof(tests)/sizeof(int(*)(void)); i++) {
+        printf("%d\n", (*tests[i])());
+    }
 }