* charset.h (DECODE_CHAR): Return int, not unsigned;

this is what was intended anyway, and it avoids undefined behavior.
(CHARSET_OFFSET): Remove unused macro, instead of fixing its
integer-overflow issues.
(ENCODE_CHAR): Return unsigned on all hosts, not just on 32-bit hosts.
Formerly, it returned EMACS_INT on 64-bit hosts in the common case
where the argument is EMACS_INT, and this behavior is not intended.

2 files changed, 11 insertions, 14 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 7973cc277e2..2e632bc5ad8 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -119,6 +119,13 @@
         (load_charset_map): Pass unsigned, not int, as 2nd arg of
         INDEX_TO_CODE_POINT, as that's what it expects.
         (Funify_charset, encode_char): Don't stuff unsigned vals into int vars.
+        * charset.h (DECODE_CHAR): Return int, not unsigned;
+        this is what was intended anyway, and it avoids undefined behavior.
+        (CHARSET_OFFSET): Remove unused macro, instead of fixing its
+        integer-overflow issues.
+        (ENCODE_CHAR): Return unsigned on all hosts, not just on 32-bit hosts.
+        Formerly, it returned EMACS_INT on 64-bit hosts in the common case
+        where the argument is EMACS_INT, and this behavior is not intended.
         * chartab.c (Fmake_char_table, Fset_char_table_range)
         (uniprop_get_decoder, uniprop_get_encoder):
         Don't assume fixnum fits in int.
diff --git a/src/charset.h b/src/charset.h
index be02bc0feae..483b7e29f7b 100644
--- a/src/charset.h
+++ b/src/charset.h
@@ -401,7 +401,7 @@ extern Lisp_Object Vchar_charset_set;
    ? decode_char ((charset), (code))                                    \
    : (charset)->method == CHARSET_METHOD_OFFSET                         \
    ? ((charset)->code_linear_p                                          \
-      ? (code) - (charset)->min_code + (charset)->code_offset           \
+      ? (int) ((code) - (charset)->min_code) + (charset)->code_offset   \
       : decode_char ((charset), (code)))                                \
    : (charset)->method == CHARSET_METHOD_MAP                            \
    ? (((charset)->code_linear_p                                         \
@@ -411,16 +411,6 @@ extern Lisp_Object Vchar_charset_set;
       : decode_char ((charset), (code)))                                \
    : decode_char ((charset), (code)))
 
-
-/* If CHARSET is a simple offset base charset, return it's offset,
-   otherwise return -1.  */
-#define CHARSET_OFFSET(charset)                         \
-  (((charset)->method == CHARSET_METHOD_OFFSET          \
-    && (charset)->code_linear_p                         \
-    && ! (charset)->unified_p)                          \
-   ? (charset)->code_offset - (charset)->min_code       \
-   : -1)
-
 extern Lisp_Object charset_work;
 
 /* Return a code point of CHAR in CHARSET.
@@ -430,7 +420,7 @@ extern Lisp_Object charset_work;
   (verify_expr                                                          \
    (sizeof (c) <= sizeof (int),                                         \
     (ASCII_CHAR_P (c) && (charset)->ascii_compatible_p                  \
-     ? (c)                                                              \
+     ? (unsigned) (c)                                                   \
      : ((charset)->unified_p                                            \
         || (charset)->method == CHARSET_METHOD_SUBSET                   \
         || (charset)->method == CHARSET_METHOD_SUPERSET)                \
@@ -439,7 +429,7 @@ extern Lisp_Object charset_work;
      ? (charset)->invalid_code                                          \
      : (charset)->method == CHARSET_METHOD_OFFSET                       \
      ? ((charset)->code_linear_p                                        \
-        ? (c) - (charset)->code_offset + (charset)->min_code            \
+        ? (unsigned) ((c) - (charset)->code_offset) + (charset)->min_code \
         : encode_char (charset, c))                                     \
      : (charset)->method == CHARSET_METHOD_MAP                          \
      ? (((charset)->compact_codes_p                                     \
@@ -447,7 +437,7 @@ extern Lisp_Object charset_work;
         ? (charset_work = CHAR_TABLE_REF (CHARSET_ENCODER (charset), c), \
            (NILP (charset_work)                                         \
             ? (charset)->invalid_code                                   \
-            : XFASTINT (charset_work)))                                 \
+            : (unsigned) XFASTINT (charset_work)))                      \
         : encode_char (charset, c))                                     \
      : encode_char (charset, c))))