[Nano-devel] [PATCH 2/5] chars: the representation of a control character is always two bytes

[Benno Schulenberg]

Any control character is represented by a ^ plus an ASCII character.
---
 src/chars.c | 19 ++++++-------------
 src/proto.h |  2 +-
 src/winio.c | 31 +++++--------------------------
 3 files changed, 12 insertions(+), 40 deletions(-)

diff --git a/src/chars.c b/src/chars.c
index d59c73c..048c816 100644
--- a/src/chars.c
+++ b/src/chars.c
@@ -253,27 +253,20 @@ wchar_t control_wrep(wchar_t wc)
 }
 #endif
 
-/* c is a multibyte control character.  It displays as ^@, ^?, or ^[ch],
- * where ch is (c + 64).  We return that single-byte character. */
-char *control_mbrep(const char *c, char *crep, int *crep_len)
+/* Return the visible representation of multibyte control character c. */
+char control_mbrep(const char *c)
 {
-    assert(c != NULL && crep != NULL && crep_len != NULL);
+    assert(c != NULL);
 
 #ifdef ENABLE_UTF8
     if (use_utf8) {
        if (0 <= c[0] && c[0] <= 127)
-           *crep = control_rep(c[0]);
+           return control_rep(c[0]);
        else
-           *crep = control_rep(c[1]);
-       *crep_len = 1;
+           return control_rep(c[1]);
     } else
 #endif
-    {
-       *crep_len = 1;
-       *crep = control_rep(*c);
-    }
-
-    return crep;
+       return control_rep(*c);
 }
 
 /* c is a multibyte non-control character.  We return that multibyte
diff --git a/src/proto.h b/src/proto.h
index cf2b4ad..0b34e6a 100644
--- a/src/proto.h
+++ b/src/proto.h
@@ -193,7 +193,7 @@ char control_rep(char c);
 #ifdef ENABLE_UTF8
 wchar_t control_wrep(wchar_t wc);
 #endif
-char *control_mbrep(const char *c, char *crep, int *crep_len);
+char control_mbrep(const char *c);
 char *mbrep(const char *c, char *crep, int *crep_len);
 int mbwidth(const char *c);
 int mb_cur_max(void);
diff --git a/src/winio.c b/src/winio.c
index 5a6892d..f5078db 100644
--- a/src/winio.c
+++ b/src/winio.c
@@ -1792,18 +1792,8 @@ char *display_string(const char *buf, size_t start_col, 
size_t len, bool
 
        if (is_cntrl_mbchar(buf_mb)) {
            if (column < start_col) {
-               char *character = charalloc(mb_cur_max());
-               int charlen, i;
-
-               character = control_mbrep(buf_mb, character, &charlen);
-
-               for (i = 0; i < charlen; i++)
-                   converted[index++] = character[i];
-
-               start_col += mbwidth(character);
-
-               free(character);
-
+               converted[index++] = control_mbrep(buf_mb);
+               start_col++;
                start_index += buf_mb_len;
            }
        }
@@ -1865,22 +1855,11 @@ char *display_string(const char *buf, size_t start_col, 
size_t len, bool
                converted[index++] = ' ';
                start_col++;
            }
-       /* If buf contains a control character, interpret it. */
+       /* If buf contains a control character, represent it. */
        } else if (is_cntrl_mbchar(buf_mb)) {
-           char *character = charalloc(mb_cur_max());
-           int charlen, i;
-
            converted[index++] = '^';
-           start_col++;
-
-           character = control_mbrep(buf_mb, character, &charlen);
-
-           for (i = 0; i < charlen; i++)
-               converted[index++] = character[i];
-
-           start_col += mbwidth(character);
-
-           free(character);
+           converted[index++] = control_mbrep(buf_mb);
+           start_col += 2;
        /* If buf contains a non-control character, interpret it.  If buf
         * contains an invalid multibyte sequence, display it as such. */
        } else {
-- 
2.8.1