1 files changed, 55 insertions, 27 deletions

diff --git a/st.c b/st.c
index 84f9abb..77ea0c8 100644
--- a/st.c
+++ b/st.c
@@ -137,6 +137,16 @@ enum term_mode {
                           |MODE_MOUSEMANY,
 };
 
+enum charset {
+        CS_GRAPHIC0,
+        CS_GRAPHIC1,
+        CS_UK,
+        CS_USA,
+        CS_MULTI,
+        CS_GER,
+        CS_FIN
+};
+
 enum escape_state {
         ESC_START      = 1,
         ESC_CSI        = 2,
@@ -216,6 +226,9 @@ typedef struct {
         int bot;      /* bottom scroll limit */
         int mode;     /* terminal mode flags */
         int esc;      /* escape state flags */
+        char trantbl[4]; /* charset table translation */
+        int charset;  /* current charset */
+        int icharset; /* selected charset for sequence */
         bool numlock; /* lock numbers in keyboard */
         bool *tabs;
 } Term;
@@ -367,6 +380,8 @@ static void tsetmode(bool, bool, int *, int);
 static void tfulldirt(void);
 static void techo(char *, int);
 static long tdefcolor(int *, int *, int);
+static void tselcs(void);
+static void tdeftran(char);
 static inline bool match(uint, uint);
 static void ttynew(void);
 static void ttyread(void);
@@ -1369,6 +1384,8 @@ treset(void) {
         term.top = 0;
         term.bot = term.row - 1;
         term.mode = MODE_WRAP;
+        memset(term.trantbl, sizeof(term.trantbl), CS_USA);
+        term.charset = 0;
 
         tclearregion(0, 0, term.col-1, term.row-1);
         tmoveto(0, 0);
@@ -2260,6 +2277,33 @@ techo(char *buf, int len) {
 }
 
 void
+tdeftran(char ascii) {
+        char c, (*bp)[2];
+        static char tbl[][2] = {
+                {'0', CS_GRAPHIC0}, {'1', CS_GRAPHIC1}, {'A', CS_UK},
+                {'B', CS_USA},      {'<', CS_MULTI},    {'K', CS_GER},
+                {'5', CS_FIN},      {'C', CS_FIN},
+                {0, 0}
+        };
+
+        for (bp = &tbl[0]; (c = (*bp)[0]) && c != ascii; ++bp)
+                /* nothing */;
+
+        if (c == 0)
+                fprintf(stderr, "esc unhandled charset: ESC ( %c\n", ascii);
+        else
+                term.trantbl[term.icharset] = (*bp)[1];
+}
+
+void
+tselcs(void) {
+        if (term.trantbl[term.charset] == CS_GRAPHIC0)
+                term.c.attr.mode |= ATTR_GFX;
+        else
+                term.c.attr.mode &= ~ATTR_GFX;
+}
+
+void
 tputc(char *c, int len) {
         uchar ascii = *c;
         bool control = ascii < '\x20' || ascii == 0177;
@@ -2351,13 +2395,12 @@ tputc(char *c, int len) {
                         term.esc = ESC_START;
                         return;
                 case '\016': /* SO */
+                        term.charset = 0;
+                        tselcs();
+                        return;
                 case '\017': /* SI */
-                        /*
-                         * Different charsets are hard to handle. Applications
-                         * should use the right alt charset escapes for the
-                         * only reason they still exist: line drawing. The
-                         * rest is incompatible history st should not support.
-                         */
+                        term.charset = 1;
+                        tselcs();
                         return;
                 case '\032': /* SUB */
                 case '\030': /* CAN */
@@ -2385,22 +2428,8 @@ tputc(char *c, int len) {
                         if(ascii == '\\')
                                 strhandle();
                 } else if(term.esc & ESC_ALTCHARSET) {
-                        switch(ascii) {
-                        case '0': /* Line drawing set */
-                                term.c.attr.mode |= ATTR_GFX;
-                                break;
-                        case 'B': /* USASCII */
-                                term.c.attr.mode &= ~ATTR_GFX;
-                                break;
-                        case 'A': /* UK (IGNORED) */
-                        case '<': /* multinational charset (IGNORED) */
-                        case '5': /* Finnish (IGNORED) */
-                        case 'C': /* Finnish (IGNORED) */
-                        case 'K': /* German (IGNORED) */
-                                break;
-                        default:
-                                fprintf(stderr, "esc unhandled charset: ESC ( %c\n", ascii);
-                        }
+                        tdeftran(ascii);
+                        tselcs();
                         term.esc = 0;
                 } else if(term.esc & ESC_TEST) {
                         if(ascii == '8') { /* DEC screen alignment test. */
@@ -2431,13 +2460,12 @@ tputc(char *c, int len) {
                                 term.esc |= ESC_STR;
                                 break;
                         case '(': /* set primary charset G0 */
+                        case ')': /* set secondary charset G1 */
+                        case '*': /* set tertiary charset G2 */
+                        case '+': /* set quaternary charset G3 */
+                                term.icharset = ascii - '(';
                                 term.esc |= ESC_ALTCHARSET;
                                 break;
-                        case ')': /* set secondary charset G1 (IGNORED) */
-                        case '*': /* set tertiary charset G2 (IGNORED) */
-                        case '+': /* set quaternary charset G3 (IGNORED) */
-                                term.esc = 0;
-                                break;
                         case 'D': /* IND -- Linefeed */
                                 if(term.c.y == term.bot) {
                                         tscrollup(term.top, 1);