Avoid writing to purespace

* src/alloc.c (Fmake_string): Don't write to empty string contents.
(allocate_vector): Don't write to empty vector size.
* src/character.h (CHECK_CHARACTER_CAR, CHECK_CHARACTER_CDR):
Don't call unnecessary XSETCAR or XSETCDR.
* src/lisp.h (STRING_SET_UNIBYTE, STRING_SET_MULTIBYTE): Don't
write to empty string size_byte.

1 files changed, 0 insertions, 2 deletions

diff --git a/src/character.h b/src/character.h
index 871c1c3de95..440e78147d1 100644
--- a/src/character.h
+++ b/src/character.h
@@ -135,14 +135,12 @@ enum
   do {                                  \
     Lisp_Object tmp = XCAR (x);         \
     CHECK_CHARACTER (tmp);              \
-    XSETCAR ((x), tmp);                 \
   } while (false)
 
 #define CHECK_CHARACTER_CDR(x) \
   do {                                  \
     Lisp_Object tmp = XCDR (x);         \
     CHECK_CHARACTER (tmp);              \
-    XSETCDR ((x), tmp);                 \
   } while (false)
 
 /* Nonzero iff C is a character of code less than 0x100.  */