Commit d4328b40 authored by Adam Tlalka's avatar Adam Tlalka Committed by Linus Torvalds
Browse files

[PATCH] console utf-8 mode fixes 



Fix utf-8 mode so alternate charset modes always work according to control
sequences interpreted in do_con_trol function preserving backward US-ASCII
and VT100 semigraphics compatibility.

Malformed utf-8 sequences are represented as sequences of replacement
glyphs,original codes or '?' as a last resort.

unicode-xterm, gnome-terminal, kconsole and other terminal emulators in
utf-8 mode respect acsc, enacs, rmacs sequences.  Also I found that some
important system programs (from Debian distro) uses acsc in utf-8 mode -
dselect, aptitude, w3m for example.

Signed-off-by: default avatarAdam Tlalka <atlka@pg.gda.pl>
Acked-by: default avatarAlan Cox <alan@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 08c67d2a

drivers/char/vt.c

+52 −27
Original line number Diff line number Diff line
@@ -63,6 +63,13 @@ 
 *

 * Removed console_lock, enabled interrupts across all console operations

 * 13 March 2001, Andrew Morton

 *

 * Fixed UTF-8 mode so alternate charset modes always work according

 * to control sequences interpreted in do_con_trol function

 * preserving backward VT100 semigraphics compatibility,

 * malformed UTF sequences represented as sequences of replacement glyphs,

 * original codes or '?' as a last resort if replacement glyph is undefined

 * by Adam Tla/lka <atlka@pg.gda.pl>, Aug 2006

 */



#include <linux/module.h>
@@ -2005,17 +2012,23 @@ static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int co 
		/* Do no translation at all in control states */

		if (vc->vc_state != ESnormal) {

			tc = c;

		} else if (vc->vc_utf) {

		} else if (vc->vc_utf && !vc->vc_disp_ctrl) {

		    /* Combine UTF-8 into Unicode */

		    /* Incomplete characters silently ignored */

		    /* Malformed sequences as sequences of replacement glyphs */

rescan_last_byte:

		    if(c > 0x7f) {

			if (vc->vc_utf_count > 0 && (c & 0xc0) == 0x80) {

			if (vc->vc_utf_count) {

			       if ((c & 0xc0) == 0x80) {

				       vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);

				vc->vc_utf_count--;

				if (vc->vc_utf_count == 0)

       				       if (--vc->vc_utf_count) {

					       vc->vc_npar++;

				   	       continue;

       				       }

				       tc = c = vc->vc_utf_char;

				else continue;

			       } else

				       goto replacement_glyph;

			} else {

				vc->vc_npar = 0;

				if ((c & 0xe0) == 0xc0) {

				    vc->vc_utf_count = 1;

				    vc->vc_utf_char = (c & 0x1f);
@@ -2032,14 +2045,15 @@ static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int co 
				    vc->vc_utf_count = 5;

				    vc->vc_utf_char = (c & 0x01);

				} else

				    vc->vc_utf_count = 0;

	    			    goto replacement_glyph;

				continue;

			      }

		    } else {

		      if (vc->vc_utf_count)

	  		      goto replacement_glyph;

		      tc = c;

		      vc->vc_utf_count = 0;

		    }

		} else {	/* no utf */

		} else {	/* no utf or alternate charset mode */

		  tc = vc->vc_translate[vc->vc_toggle_meta ? (c | 0x80) : c];

		}
@@ -2054,31 +2068,33 @@ static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int co 
                 * direct-to-font zone in UTF-8 mode.

                 */

                ok = tc && (c >= 32 ||

			    (!vc->vc_utf && !(((vc->vc_disp_ctrl ? CTRL_ALWAYS

						: CTRL_ACTION) >> c) & 1)))

			    !(vc->vc_disp_ctrl ? (CTRL_ALWAYS >> c) & 1 :

				  vc->vc_utf || ((CTRL_ACTION >> c) & 1)))

			&& (c != 127 || vc->vc_disp_ctrl)

			&& (c != 128+27);



		if (vc->vc_state == ESnormal && ok) {

			/* Now try to find out how to display it */

			tc = conv_uni_to_pc(vc, tc);

			if (tc & ~charmask) {

				if ( tc == -4 ) {

                                /* If we got -4 (not found) then see if we have

                                   defined a replacement character (U+FFFD) */

replacement_glyph:

                                	tc = conv_uni_to_pc(vc, 0xfffd);



				/* One reason for the -4 can be that we just

				   did a clear_unimap();

				   try at least to show something. */

				if (tc == -4)

				     tc = c;

                        } else if ( tc == -3 ) {

                                /* Bad hash table -- hope for the best */

					if (!(tc & ~charmask))

						goto display_glyph;

                        	} else if ( tc != -3 )

                                	continue; /* nothing to display */

                                /* no hash table or no replacement --

				 * hope for the best */

				if ( c & ~charmask )

					tc = '?';

				else

					tc = c;

			}

			if (tc & ~charmask)

                                continue; /* Conversion failed */



display_glyph:

			if (vc->vc_need_wrap || vc->vc_decim)

				FLUSH

			if (vc->vc_need_wrap) {
@@ -2102,6 +2118,15 @@ static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int co 
				vc->vc_x++;

				draw_to = (vc->vc_pos += 2);

			}

			if (vc->vc_utf_count) {

				if (vc->vc_npar) {

					vc->vc_npar--;

					goto display_glyph;

				}

				vc->vc_utf_count = 0;

				c = orig;

				goto rescan_last_byte;

			}

			continue;

		}

		FLUSH

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