X-Git-Url: https://git.distorted.org.uk/~mdw/sgt/charset/blobdiff_plain/ee45694b123040008ffadc8cb5182ce7041e84b2..7804475c3f05dfeb234d7a3e7578a2db2c5562c8:/iso2022s.c

diff --git a/iso2022s.c b/iso2022s.c
index 087fd96..000c57e 100644
--- a/iso2022s.c
+++ b/iso2022s.c
@@ -42,7 +42,7 @@ struct iso2022 {
      * in ASCII order, so that we can narrow down the list as
      * necessary.
      */
-    struct iso2022_escape *escapes;    /* must be sorted in ASCII order! */
+    const struct iso2022_escape *escapes;/* must be sorted in ASCII order! */
     int nescapes;
 
     /*
@@ -482,13 +482,13 @@ static int iso2022jp_from_ucs(long int ucs, int *subcharset,
 	return 0;
     }
 }
-static struct iso2022_escape iso2022jp_escapes[] = {
+static const struct iso2022_escape iso2022jp_escapes[] = {
     {"\033$@", 0xFFFFFFC0, 0x00000002, -1, -1},   /* we ignore this one */
     {"\033$B", 0xFFFFFFC0, 0x00000002, 0, 2},
     {"\033(B", 0xFFFFFFC0, 0x00000000, 0, 0},
     {"\033(J", 0xFFFFFFC0, 0x00000001, 0, 1},
 };
-static struct iso2022 iso2022jp = {
+static const struct iso2022 iso2022jp = {
     iso2022jp_escapes, lenof(iso2022jp_escapes),
     "\1\1\2", "\3", 0x80000000, NULL, FALSE,
     iso2022jp_to_ucs, iso2022jp_from_ucs
@@ -525,12 +525,12 @@ static int iso2022kr_from_ucs(long int ucs, int *subcharset,
 	return 0;
     }
 }
-static struct iso2022_escape iso2022kr_escapes[] = {
+static const struct iso2022_escape iso2022kr_escapes[] = {
     {"\016", 0x8FFFFFFF, 0x10000000, -1, -1},
     {"\017", 0x8FFFFFFF, 0x00000000, 0, 0},
     {"\033$)C", 0xFFFFF03F, 0x00000040, 1, 1},   /* bits[11:6] <- 1 */
 };
-static struct iso2022 iso2022kr = {
+static const struct iso2022 iso2022kr = {
     iso2022kr_escapes, lenof(iso2022kr_escapes),
     "\1\2", "\2", 0x80000040, "\033$)C", FALSE,
     iso2022kr_to_ucs, iso2022kr_from_ucs
@@ -562,7 +562,8 @@ enum {
     CTEXT_ISO8859_9,
     CTEXT_GB2312,
     CTEXT_KSC5601,
-    CTEXT_JISX0208
+    CTEXT_JISX0208,
+    CTEXT_JISX0212
 };
 static long int ctext_to_ucs(int subcharset, unsigned long bytes)
 {
@@ -599,6 +600,9 @@ static long int ctext_to_ucs(int subcharset, unsigned long bytes)
       case CTEXT_JISX0208:
 	return jisx0208_to_unicode(((bytes >> 8) & 0xFF) - 0x21,
 				   ((bytes     ) & 0xFF) - 0x21);
+      case CTEXT_JISX0212:
+	return jisx0212_to_unicode(((bytes >> 8) & 0xFF) - 0x21,
+				   ((bytes     ) & 0xFF) - 0x21);
       default: return ERROR;
     }
 }
@@ -666,12 +670,16 @@ static int ctext_from_ucs(long int ucs, int *subcharset, unsigned long *bytes)
 	*subcharset = CTEXT_JISX0208;
 	*bytes = ((r+0x21) << 8) | (c+0x21);
 	return 1;
+    } else if (unicode_to_jisx0212(ucs, &r, &c)) {
+	*subcharset = CTEXT_JISX0212;
+	*bytes = ((r+0x21) << 8) | (c+0x21);
+	return 1;
     } else {
 	return 0;
     }
 }
 #define SEQ(str,cont,cs) \
-    {str,~(63<<(6*((cont&~RO)))),(cs)<<(6*((cont&~RO))),(cont),(cs)}
+    {str,~(63<<(6*(((cont)&~RO)))),(cs)<<(6*(((cont)&~RO))),(cont),(cs)}
 /*
  * Compound text defines restrictions on which container can take
  * which character sets. Things labelled `left half of' can only go
@@ -684,13 +692,15 @@ static int ctext_from_ucs(long int ucs, int *subcharset, unsigned long *bytes)
  *    in either; we prefer GR where possible since this leads to a
  *    more compact EUC-like encoding.
  */
-static struct iso2022_escape ctext_escapes[] = {
+static const struct iso2022_escape ctext_escapes[] = {
     SEQ("\033$(A", 0|RO, CTEXT_GB2312),
     SEQ("\033$(B", 0|RO, CTEXT_JISX0208),
     SEQ("\033$(C", 0|RO, CTEXT_KSC5601),
+    SEQ("\033$(D", 0|RO, CTEXT_JISX0212),
     SEQ("\033$)A", 1, CTEXT_GB2312),
     SEQ("\033$)B", 1, CTEXT_JISX0208),
     SEQ("\033$)C", 1, CTEXT_KSC5601),
+    SEQ("\033$)D", 1, CTEXT_JISX0212),
     SEQ("\033(B", 0, CTEXT_ASCII),
     SEQ("\033(J", 0, CTEXT_JISX0201_LEFT),
     SEQ("\033)I", 1, CTEXT_JISX0201_RIGHT),
@@ -703,10 +713,37 @@ static struct iso2022_escape ctext_escapes[] = {
     SEQ("\033-H", 1, CTEXT_ISO8859_8),
     SEQ("\033-L", 1, CTEXT_ISO8859_5),
     SEQ("\033-M", 1, CTEXT_ISO8859_9),
+
+    /*
+     * Cross-testing against Xutf8TextListToTextProperty() turns up
+     * some additional character sets and ISO 2022 features
+     * supported by that and not by us:
+     * 
+     * 	- Single-byte right-hand-half character sets `ESC - f',
+     * 	  `ESC - T' and `ESC - Y'.
+     * 
+     * 	- A really horrifying mechanism used to escape completely
+     * 	  from the ISO 2022 framework: ESC % / <length>
+     * 	  <charset-name> <text>. Xutf8* uses this to encode
+     * 	  "iso8859-14", "iso8859-15" and "big5-0".
+     * 	   * This mechanism is particularly nasty because we can't
+     * 	     efficiently encode it on the fly! It requires that the
+     * 	     length of the text encoded in the foreign charset is
+     * 	     given _before_ the text in question, so if we're
+     * 	     receiving one character at a time we simply can't look
+     * 	     ahead and so we would have to encode each individual
+     * 	     character in a separate one of these sequences.
+     * 
+     * 	- ESC % G and ESC % @ to shift to and from UTF-8 mode, as a
+     * 	  last resort for anything we still don't support.
+     * 	   * Interestingly, ctext.ps actually _disallows_ this: it
+     * 	     says that the above extension mechanism is the only
+     * 	     one permitted. Ho hum.
+     */
 };
-static struct iso2022 ctext = {
+static const struct iso2022 ctext = {
     ctext_escapes, lenof(ctext_escapes),
-    "\1\1\1\1\1\1\1\1\1\1\1\1\2\2\2",  /* must match the enum above */
+    "\1\1\1\1\1\1\1\1\1\1\1\1\2\2\2\2",  /* must match the enum above */
     "", 0x80000000 | (CTEXT_ASCII<<0) | (CTEXT_ISO8859_1<<6), "", TRUE,
     ctext_to_ucs, ctext_from_ucs
 };