--- a/src/macros.h
+++ b/src/macros.h
@@ -8,6 +8,9 @@
 
 /*
  * macros.h: macro definitions for often used code
+ *
+ * Macros should be ALL_CAPS.  An exception is for where a function is
+ * replaced and an argument is not used more than once.
  */
 
 /*
@@ -161,10 +164,10 @@
 #endif
 
 /*
- * vim_isbreak() is used very often if 'linebreak' is set, use a macro to make
- * it work fast.
+ * VIM_ISBREAK() is used very often if 'linebreak' is set, use a macro to make
+ * it work fast.  Only works for single byte characters!
  */
-#define vim_isbreak(c) (breakat_flags[(char_u)(c)])
+#define VIM_ISBREAK(c) ((c) < 256 && breakat_flags[(char_u)(c)])
 
 /*
  * On VMS file names are different and require a translation.
@@ -190,9 +193,7 @@
 #  define mch_stat(n, p)	vim_stat((n), (p))
 # else
 #  ifdef STAT_IGNORES_SLASH
-    /* On Solaris stat() accepts "file/" as if it was "file".  Return -1 if
-     * the name ends in "/" and it's not a directory. */
-#   define mch_stat(n, p)	(illegal_slash(n) ? -1 : stat((n), (p)))
+#   define mch_stat(n, p)	vim_stat((n), (p))
 #  else
 #   define mch_stat(n, p)	stat((n), (p))
 #  endif
@@ -258,22 +259,22 @@
 #endif
 
 /*
- * mb_ptr_adv(): advance a pointer to the next character, taking care of
+ * MB_PTR_ADV(): advance a pointer to the next character, taking care of
  * multi-byte characters if needed.
- * mb_ptr_back(): backup a pointer to the previous character, taking care of
+ * MB_PTR_BACK(): backup a pointer to the previous character, taking care of
  * multi-byte characters if needed.
  * MB_COPY_CHAR(f, t): copy one char from "f" to "t" and advance the pointers.
  * PTR2CHAR(): get character from pointer.
  */
 #ifdef FEAT_MBYTE
 /* Get the length of the character p points to */
-# define MB_PTR2LEN(p)		(has_mbyte ? (*mb_ptr2len)(p) : 1)
+# define MB_PTR2LEN(p)	    (has_mbyte ? (*mb_ptr2len)(p) : 1)
 /* Advance multi-byte pointer, skip over composing chars. */
-# define mb_ptr_adv(p)	    p += has_mbyte ? (*mb_ptr2len)(p) : 1
+# define MB_PTR_ADV(p)	    p += has_mbyte ? (*mb_ptr2len)(p) : 1
 /* Advance multi-byte pointer, do not skip over composing chars. */
-# define mb_cptr_adv(p)	    p += enc_utf8 ? utf_ptr2len(p) : has_mbyte ? (*mb_ptr2len)(p) : 1
+# define MB_CPTR_ADV(p)	    p += enc_utf8 ? utf_ptr2len(p) : has_mbyte ? (*mb_ptr2len)(p) : 1
 /* Backup multi-byte pointer. Only use with "p" > "s" ! */
-# define mb_ptr_back(s, p)  p -= has_mbyte ? ((*mb_head_off)(s, p - 1) + 1) : 1
+# define MB_PTR_BACK(s, p)  p -= has_mbyte ? ((*mb_head_off)(s, p - 1) + 1) : 1
 /* get length of multi-byte char, not including composing chars */
 # define MB_CPTR2LEN(p)	    (enc_utf8 ? utf_ptr2len(p) : (*mb_ptr2len)(p))
 
@@ -284,9 +285,9 @@
 #else
 # define MB_PTR2LEN(p)		1
 # define MB_CPTR2LEN(p)		1
-# define mb_ptr_adv(p)		++p
-# define mb_cptr_adv(p)		++p
-# define mb_ptr_back(s, p)	--p
+# define MB_PTR_ADV(p)		++p
+# define MB_CPTR_ADV(p)		++p
+# define MB_PTR_BACK(s, p)	--p
 # define MB_COPY_CHAR(f, t)	*t++ = *f++
 # define MB_CHARLEN(p)		STRLEN(p)
 # define MB_CHAR2LEN(c)		1