Misc minor simplifications in C code.

* src/buffer.c (Fset_buffer_multibyte): Signal an error instead of widening.
(Fmake_overlay): Remove redundant tests.
* src/coding.h (ENCODE_FILE, DECODE_FILE, DECODE_SYSTEM): Remove special
case for the special 0 coding-system.
* src/frame.c (Fmake_terminal_frame): Prefer safer CONSP over !NILP.

1 files changed, 0 insertions, 6 deletions

diff --git a/src/coding.h b/src/coding.h
index c45d2ef86e2..989552bf667 100644
--- a/src/coding.h
+++ b/src/coding.h
@@ -646,10 +646,8 @@ struct coding_system
    for file names, if any.  */
 #define ENCODE_FILE(name)                                                  \
   (! NILP (Vfile_name_coding_system)                                       \
-   && !EQ (Vfile_name_coding_system, make_number (0))                      \
    ? code_convert_string_norecord (name, Vfile_name_coding_system, 1)      \
    : (! NILP (Vdefault_file_name_coding_system)                            \
-      && !EQ (Vdefault_file_name_coding_system, make_number (0))           \
       ? code_convert_string_norecord (name, Vdefault_file_name_coding_system, 1) \
       : name))
 
@@ -658,10 +656,8 @@ struct coding_system
    for file names, if any.  */
 #define DECODE_FILE(name)                                                  \
   (! NILP (Vfile_name_coding_system)                                       \
-   && !EQ (Vfile_name_coding_system, make_number (0))                      \
    ? code_convert_string_norecord (name, Vfile_name_coding_system, 0)      \
    : (! NILP (Vdefault_file_name_coding_system)                            \
-      && !EQ (Vdefault_file_name_coding_system, make_number (0))           \
       ? code_convert_string_norecord (name, Vdefault_file_name_coding_system, 0) \
       : name))
 
@@ -670,7 +666,6 @@ struct coding_system
    for system functions, if any.  */
 #define ENCODE_SYSTEM(str)                                                 \
   (! NILP (Vlocale_coding_system)                                          \
-   && !EQ (Vlocale_coding_system, make_number (0))                         \
    ? code_convert_string_norecord (str, Vlocale_coding_system, 1)          \
    : str)
 
@@ -678,7 +673,6 @@ struct coding_system
    for system functions, if any.  */
 #define DECODE_SYSTEM(str)                                                 \
   (! NILP (Vlocale_coding_system)                                          \
-   && !EQ (Vlocale_coding_system, make_number (0))                         \
    ? code_convert_string_norecord (str, Vlocale_coding_system, 0)          \
    : str)