fixup! Fix misaligned pointer conversion

Author: adombeck

internal/users/localentries/getgrent_c.go

@@ -8,18 +8,13 @@ package localentries
 #include <pwd.h>
 #include <grp.h>
 
-// Copy a NULL-terminated char** into a new array and return length.
-char **copy_strv(char **strv, int *out_len) {
+// Return the length of a NULL-terminated char** array.
+int strv_len(char **strv) {
     int n = 0;
     while (strv && strv[n]) n++;
-
-    *out_len = n;
-    char **out = calloc(n + 1, sizeof(char*));
-    for (int i = 0; i < n; i++) {
-        out[i] = strv[i];
-    }
-    return out;
+    return n;
 }
+
 */
 import "C"
 
@@ -90,13 +85,11 @@ func strvToSlice(strv **C.char) []string {
 	if strv == nil {
 		return nil
 	}
-	var n C.int
-	tmp := C.copy_strv(strv, &n)
-	defer C.free(unsafe.Pointer(tmp))
+	n := C.strv_len(strv)
 
 	out := make([]string, int(n))
 	for i := 0; i < int(n); i++ {
-		p := *(**C.char)(unsafe.Add(unsafe.Pointer(tmp), uintptr(i)*unsafe.Sizeof(*tmp)))
+		p := *(**C.char)(unsafe.Add(unsafe.Pointer(strv), uintptr(i)*unsafe.Sizeof(*strv)))
 		out[i] = C.GoString(p)
 	}
 	return out