cleanup: remove legacy `enc_dbcs` global #9660

8 files changed, 27 insertions, 71 deletions

diff --git a/src/nvim/edit.c b/src/nvim/edit.c
index 5a21c50fa6..67ac675a14 100644
--- a/src/nvim/edit.c
+++ b/src/nvim/edit.c
@@ -5110,11 +5110,9 @@ int get_literal(void)
     }
   }
 
-  if (cc == 0)          /* NUL is stored as NL */
+  if (cc == 0) {        // NUL is stored as NL
     cc = '\n';
-  if (enc_dbcs && (cc & 0xff) == 0)
-    cc = '?';           /* don't accept an illegal DBCS char, the NUL in the
-                           second byte will cause trouble! */
+  }
 
   --no_mapping;
   if (nc)
diff --git a/src/nvim/ex_docmd.c b/src/nvim/ex_docmd.c
index cda80dad39..bbec977c74 100644
--- a/src/nvim/ex_docmd.c
+++ b/src/nvim/ex_docmd.c
@@ -5489,24 +5489,18 @@ uc_check_code(
       break;
     case 1:     /* Quote, but don't split */
       result = STRLEN(eap->arg) + 2;
-      for (p = eap->arg; *p; ++p) {
-        if (enc_dbcs != 0 && (*mb_ptr2len)(p) == 2)
-          /* DBCS can contain \ in a trail byte, skip the
-           * double-byte character. */
-          ++p;
-        else if (*p == '\\' || *p == '"')
-          ++result;
+      for (p = eap->arg; *p; p++) {
+        if (*p == '\\' || *p == '"') {
+          result++;
+        }
       }
 
       if (buf != NULL) {
         *buf++ = '"';
-        for (p = eap->arg; *p; ++p) {
-          if (enc_dbcs != 0 && (*mb_ptr2len)(p) == 2)
-            /* DBCS can contain \ in a trail byte, copy the
-             * double-byte character to avoid escaping. */
-            *buf++ = *p++;
-          else if (*p == '\\' || *p == '"')
+        for (p = eap->arg; *p; p++) {
+          if (*p == '\\' || *p == '"') {
             *buf++ = '\\';
+          }
           *buf++ = *p;
         }
         *buf = '"';
diff --git a/src/nvim/fileio.c b/src/nvim/fileio.c
index ba3625bf95..b9de46efc8 100644
--- a/src/nvim/fileio.c
+++ b/src/nvim/fileio.c
@@ -5313,9 +5313,7 @@ void forward_slash(char_u *fname)
   }
   for (p = fname; *p != NUL; p++) {
     // The Big5 encoding can have '\' in the trail byte.
-    if (enc_dbcs != 0 && (*mb_ptr2len)(p) > 1) {
-      p++;
-    } else if (*p == '\\') {
+    if (*p == '\\') {
       *p = '/';
     }
   }
@@ -7615,10 +7613,6 @@ char_u * file_pat_to_reg_pat(
 #endif
     default:
       size++;
-      if (enc_dbcs != 0 && (*mb_ptr2len)(p) > 1) {
-        ++p;
-        ++size;
-      }
       break;
     }
   }
@@ -7739,10 +7733,9 @@ char_u * file_pat_to_reg_pat(
         reg_pat[i++] = ',';
       break;
     default:
-      if (enc_dbcs != 0 && (*mb_ptr2len)(p) > 1)
-        reg_pat[i++] = *p++;
-      else if (allow_dirs != NULL && vim_ispathsep(*p))
-        *allow_dirs = TRUE;
+      if (allow_dirs != NULL && vim_ispathsep(*p)) {
+        *allow_dirs = true;
+      }
       reg_pat[i++] = *p;
       break;
     }
diff --git a/src/nvim/globals.h b/src/nvim/globals.h
index a988af79b2..1e2c6eea59 100644
--- a/src/nvim/globals.h
+++ b/src/nvim/globals.h
@@ -641,7 +641,6 @@ EXTERN int vr_lines_changed INIT(= 0);      /* #Lines changed by "gR" so far */
 // mbyte flags that used to depend on 'encoding'. These are now deprecated, as
 // 'encoding' is always "utf-8". Code that use them can be refactored to
 // remove dead code.
-#define enc_dbcs 0
 #define enc_utf8 true
 #define has_mbyte true
 
diff --git a/src/nvim/mbyte.c b/src/nvim/mbyte.c
index 1cf045d7e0..5ed2b4c564 100644
--- a/src/nvim/mbyte.c
+++ b/src/nvim/mbyte.c
@@ -4,9 +4,8 @@
 /// mbyte.c: Code specifically for handling multi-byte characters.
 /// Multibyte extensions partly by Sung-Hoon Baek
 ///
-/// The encoding used in nvim is always UTF-8. "enc_utf8" and "has_mbyte" is
-/// thus always true. "enc_dbcs" is always zero. The 'encoding' option is
-/// read-only and always reads "utf-8".
+/// Strings internal to Nvim are always encoded as UTF-8 (thus the legacy
+/// 'encoding' option is always "utf-8").
 ///
 /// The cell width on the display needs to be determined from the character
 /// value. Recognizing UTF-8 bytes is easy: 0xxx.xxxx is a single-byte char,
diff --git a/src/nvim/message.c b/src/nvim/message.c
index b22508c23f..9a0a3565ea 100644
--- a/src/nvim/message.c
+++ b/src/nvim/message.c
@@ -281,15 +281,9 @@ msg_strtrunc (
       /* Use up to 'showcmd' column. */
       room = (int)(Rows - msg_row - 1) * Columns + sc_col - 1;
     if (len > room && room > 0) {
-      if (enc_utf8)
-        /* may have up to 18 bytes per cell (6 per char, up to two
-         * composing chars) */
-        len = (room + 2) * 18;
-      else if (enc_dbcs == DBCS_JPNU)
-        /* may have up to 2 bytes per cell for euc-jp */
-        len = (room + 2) * 2;
-      else
-        len = room + 2;
+      // may have up to 18 bytes per cell (6 per char, up to two
+      // composing chars)
+      len = (room + 2) * 18;
       buf = xmalloc(len);
       trunc_string(s, buf, room, len);
     }
diff --git a/src/nvim/ops.c b/src/nvim/ops.c
index 674a9244f0..9d9ee0c9e3 100644
--- a/src/nvim/ops.c
+++ b/src/nvim/ops.c
@@ -1974,8 +1974,6 @@ int swapchar(int op_type, pos_T *pos)
     inc(pos);
   }
 
-  if (enc_dbcs != 0 && c >= 0x100)      /* No lower/uppercase letter */
-    return FALSE;
   nc = c;
   if (mb_islower(c)) {
     if (op_type == OP_ROT13) {
diff --git a/src/nvim/search.c b/src/nvim/search.c
index d635763acc..5566df74ef 100644
--- a/src/nvim/search.c
+++ b/src/nvim/search.c
@@ -3229,37 +3229,18 @@ static int in_html_tag(int end_tag)
   int lc = NUL;
   pos_T pos;
 
-  if (enc_dbcs) {
-    char_u  *lp = NULL;
-
-    /* We search forward until the cursor, because searching backwards is
-     * very slow for DBCS encodings. */
-    for (p = line; p < line + curwin->w_cursor.col; MB_PTR_ADV(p)) {
-      if (*p == '>' || *p == '<') {
-        lc = *p;
-        lp = p;
-      }
-    }
-    if (*p != '<') {        // check for '<' under cursor
-      if (lc != '<') {
-        return false;
-      }
-      p = lp;
-    }
-  } else {
-    for (p = line + curwin->w_cursor.col; p > line; ) {
-      if (*p == '<') {           // find '<' under/before cursor
-        break;
-      }
-      MB_PTR_BACK(line, p);
-      if (*p == '>') {           // find '>' before cursor
-        break;
-      }
+  for (p = line + curwin->w_cursor.col; p > line; ) {
+    if (*p == '<') {           // find '<' under/before cursor
+      break;
     }
-    if (*p != '<') {
-      return false;
+    MB_PTR_BACK(line, p);
+    if (*p == '>') {           // find '>' before cursor
+      break;
     }
   }
+  if (*p != '<') {
+    return false;
+  }
 
   pos.lnum = curwin->w_cursor.lnum;
   pos.col = (colnr_T)(p - line);