Unify -D option and color handling between MS-DOS and non-MS-DOS builds.

less.nro.VER

@@ -570,10 +570,7 @@ The \-d option does not otherwise change the behavior of
 .I less
 on a dumb terminal.
 .IP "\-D\fBx\fP\fIcolor\fP or \-\-color=\fBx\fP\fIcolor\fP"
-[this section is for non-MS-DOS systems only; for MS-DOS systems see below]
-.br
-When the \-\-use-color option is enabled, this option 
-changes the color of different parts of the displayed text.
+Changes the color of different parts of the displayed text.
 \fBx\fP is a single character which selects the type of text 
 whose color is being set:
 .RS
@@ -595,12 +592,30 @@ The rscroll character.
 Search results.
 .IP "W"
 The highlight enabled via the \-w option.
+.IP "d"
+Bold text.
+.IP "k"
+Blinking text.
+.IP "s"
+Standout text.
+.IP "u"
+Underlined text.
 .RE
-.PP
+ 
 .RS
-\fIcolor\fP is either a 4-bit color string or a 6-bit color string:
+The uppercase letters can be used only when the \-\-use-color option is enabled.
+When text color is specified by both an uppercase letter and a lowercase letter,
+the uppercase letter takes precedence. 
+For example, error messages are normally displayed as standout text.
+So if both "s" and "E" are given a color, the "E" color applies
+to error messages, and the "s" color applies to other standout text.
+The "d" and "u" letters refer to bold and underline text formed by 
+overstriking with backspaces (see the \-u option), 
+not to text using ANSI escape sequences with the \-R option.
+.PP
+\fIcolor\fP is either a 4-bit color string or a 8-bit color string:
 .PP
-A 4-bit color string is one or two characters where 
+A 4-bit color string is zero, one or two characters, where 
 the first character specifies the foreground color and 
 the second specifies the background color as follows:
 .IP "b"
@@ -621,38 +636,27 @@ White
 Yellow
 .PP
 The corresponding upper-case letter denotes a brighter shade of the color.
-For example, \-DLGk displays line numbers as bright green text on a black 
+For example, \-DNGk displays line numbers as bright green text on a black 
 background, and \-DEbR displays error messages as blue text on a 
 bright red background.
-If either character is a "-", the corresponding color is not changed.
-If the background character is omitted, the background color is not changed.
+If either character is a "-" or is omitted, the corresponding color 
+is set to that of normal text.
 .PP
-A 6-bit color string is one or two decimal integers separated by a dot,
+A 8-bit color string is one or two decimal integers separated by a dot,
 where the first integer specifies the foreground color and 
 the second specifies the background color.
 Each integer is a value between 0 and 255 inclusive which selects
 a CSI 38;5 color (see
 .br
 https://en.wikipedia.org/wiki/ANSI_escape_code#SGR_parameters)
-If either integer is a "-", the corresponding color is not changed.
-If the dot and background integer are omitted, the background color is not changed.
+If either integer is a "-" or is omitted,
+the corresponding color is set to that of normal text.
+On MS-DOS versions of 
+.IR less ,
+8-bit color is not supported; instead, decimal values are interpreted as 4-bit
+CHAR_INFO.Attributes values
+(see https://docs.microsoft.com/en-us/windows/console/char-info-str).
 .RE
-.IP "\-D\fBx\fP\fIcolor\fP or \-\-color=\fBx\fP\fIcolor\fP"
-[this section is for MS-DOS systems only]
-.br
-Sets the color of the text displayed.
-\fBx\fP is a single character which selects the type of text whose color is
-being set: n=normal, s=standout, d=bold, u=underlined, k=blink.
-\fIcolor\fP is a pair of numbers separated by a period.
-The first number selects the foreground color and the second selects
-the background color of the text.
-A single number \fIN\fP is the same as \fIN.M\fP,
-where \fIM\fP is the normal background color.
-The color may start or end with \fBu\fP to use underline (with the normal
-color, if by itself), if the system supports it (Windows only).
-\fBx\fP may also be \fBa\fP to toggle strict ANSI sequence rendering
-(SGR mode).
-.
 .IP "\-e or \-\-quit-at-eof"
 Causes
 .I less

line.c

@@ -94,6 +94,10 @@ static char color_map[AT_NUM_COLORS][12] = {
  "kC", /* AT_COLOR_PROMPT */
  "kc", /* AT_COLOR_RSCROLL */
  "kG", /* AT_COLOR_SEARCH */
+ "", /* AT_UNDERLINE */
+ "", /* AT_BOLD */
+ "", /* AT_BLINK */
+ "", /* AT_STANDOUT */
 };
 
 /* State while processing an ANSI escape sequence */
@@ -953,7 +957,8 @@ store_bs(ch, rep, pos)
 {
  if (bs_mode == BS_CONTROL)
  return store_control_char(ch, rep, pos);
- if (linebuf.end <= linebuf.print ||
+ if (linebuf.end > 0 &&
+ (linebuf.end <= linebuf.print && linebuf.buf[linebuf.end-1] == '\0') ||
  (linebuf.end > 0 && linebuf.attr[linebuf.end - 1] & (AT_ANSI|AT_BINARY)))
  STORE_PRCHAR('\b', pos);
  else if (bs_mode == BS_NORMAL)
@@ -1407,10 +1412,30 @@ rrshift(VOID_PARAM)
 color_index(attr)
  int attr;
 {
- int cx = (attr & AT_COLOR) >> AT_COLOR_SHIFT;
- if (cx == 0 || cx > AT_NUM_COLORS)
- return -1;
- return cx-1;
+ if (use_color)
+ {
+ switch (attr & AT_COLOR)
+ {
+ case AT_COLOR_ATTN: return 0;
+ case AT_COLOR_BIN: return 1;
+ case AT_COLOR_CTRL: return 2;
+ case AT_COLOR_ERROR: return 3;
+ case AT_COLOR_LINENUM: return 4;
+ case AT_COLOR_MARK: return 5;
+ case AT_COLOR_PROMPT: return 6;
+ case AT_COLOR_RSCROLL: return 7;
+ case AT_COLOR_SEARCH: return 8;
+ }
+ }
+ if (attr & AT_UNDERLINE)
+ return 9;
+ if (attr & AT_BOLD)
+ return 10;
+ if (attr & AT_BLINK)
+ return 11;
+ if (attr & AT_STANDOUT)
+ return 12;
+ return -1;
 }
 
  static int
@@ -1431,10 +1456,11 @@ set_color_map(attr, colorstr)
  int cx = color_index(attr);
  if (cx < 0)
  return -1;
- if (tput_color(colorstr, null_putc) < 0)
+ if (*colorstr != '\0' && tput_color(colorstr, null_putc) < 0)
+ return -1;
+ if (strlen(colorstr)+1 > sizeof(color_map[cx]))
  return -1;
- strncpy(color_map[cx], colorstr, sizeof(color_map[cx]));
- color_map[cx][strlen(colorstr)] = '\0';
+ strcpy(color_map[cx], colorstr);
  return 0;
 }
 
@@ -1445,10 +1471,7 @@ set_color_map(attr, colorstr)
 get_color_map(attr)
  int attr;
 {
- int cx;
- if (!use_color)
- return NULL;
- cx = color_index(attr);
+ int cx = color_index(attr);
  if (cx < 0)
  return NULL;
  return color_map[cx];

optfunc.c

@@ -50,6 +50,7 @@ extern int wheel_lines;
 extern int less_is_more;
 extern int linenum_width;
 extern int status_col_width;
+extern int use_color;
 #if LOGFILE
 extern char *namelogfile;
 extern int force_logfile;
@@ -585,59 +586,7 @@ colordesc(s, fg_color, bg_color)
  *fg_color = fg;
  *bg_color = bg;
 }
-
-/*
- * Handler for the -D option.
- */
- /*ARGSUSED*/
- public void
-opt_D(type, s)
- int type;
- char *s;
-{
- PARG p;
-
- switch (type)
- {
- case INIT:
- case TOGGLE:
- switch (*s++)
- {
- case 'n':
- colordesc(s, &nm_fg_color, &nm_bg_color);
- break;
- case 'd':
- colordesc(s, &bo_fg_color, &bo_bg_color);
- break;
- case 'u':
- colordesc(s, &ul_fg_color, &ul_bg_color);
- break;
- case 'k':
- colordesc(s, &bl_fg_color, &bl_bg_color);
- break;
- case 's':
- colordesc(s, &so_fg_color, &so_bg_color);
- break;
- case 'a':
- sgr_mode = !sgr_mode;
- break;
- default:
- error("-D must be followed by n, d, u, k, s or a", NULL_PARG);
- break;
- }
- if (type == TOGGLE)
- {
- at_enter(AT_STANDOUT);
- at_exit();
- }
- break;
- case QUERY:
- p.p_string = (sgr_mode) ? "on" : "off";
- error("SGR mode is %s", &p);
- break;
- }
-}
-#else
+#endif
 
  static int
 color_from_namechar(namechar)
@@ -654,6 +603,10 @@ color_from_namechar(namechar)
  case 'P': return AT_COLOR_PROMPT;
  case 'R': return AT_COLOR_RSCROLL;
  case 'S': return AT_COLOR_SEARCH;
+ case 's': return AT_STANDOUT;
+ case 'd': return AT_BOLD;
+ case 'u': return AT_UNDERLINE;
+ case 'k': return AT_BLINK;
  default: return 0;
  }
 }
@@ -674,23 +627,68 @@ opt_D(type, s)
  {
  case INIT:
  case TOGGLE:
+#if MSDOS_COMPILER
+ if (*s == 'a')
+ {
+ sgr_mode = !sgr_mode;
+ break;
+ }
+#endif
  attr = color_from_namechar(s[0]);
- if (attr <= 0)
+ if (attr == 0)
  {
  p.p_char = s[0];
  error("Invalid color specifier '%c'", &p);
  return;
  }
+ if (!use_color && (attr & AT_COLOR))
+ {
+ error("Set --use-color before changing colors", NULL_PARG);
+ return;
+ }
+#if MSDOS_COMPILER
+ if (!(attr & AT_COLOR))
+ {
+ switch (attr)
+ {
+ case AT_NORMAL:
+ colordesc(s, &nm_fg_color, &nm_bg_color);
+ break;
+ case AT_BOLD:
+ colordesc(s, &bo_fg_color, &bo_bg_color);
+ break;
+ case AT_UNDERLINE:
+ colordesc(s, &ul_fg_color, &ul_bg_color);
+ break;
+ case AT_BLINK:
+ colordesc(s, &bl_fg_color, &bl_bg_color);
+ break;
+ case AT_STANDOUT:
+ colordesc(s, &so_fg_color, &so_bg_color);
+ break;
+ }
+ if (type == TOGGLE)
+ {
+ at_enter(AT_STANDOUT);
+ at_exit();
+ }
+ } else
+#endif
  if (set_color_map(attr, s+1) < 0)
  {
  p.p_string = s+1;
  error("Invalid color string \"%s\"", &p);
  return;
  }
  break;
+#if MSDOS_COMPILER
+ case QUERY:
+ p.p_string = (sgr_mode) ? "on" : "off";
+ error("SGR mode is %s", &p);
+ break;
+#endif
  }
 }
-#endif
 
 /*
  * Handler for the -x option.