(INC_POSITION): Handle format other than utf8 and utf16.

(DEC_POSITION): Likewise.

diff --git a/src/mtext.c b/src/mtext.c
index ab3b350..0bb8f59 100644 (file)
--- a/src/mtext.c
+++ b/src/mtext.c
@@ -104,53 +104,57 @@ static enum MTextFormat default_utf_16 = MTEXT_FORMAT_UTF_16LE;
 static enum MTextFormat default_utf_32 = MTEXT_FORMAT_UTF_32LE;
 #endif
 
-/** Increment character position CHAR_POS and byte position BYTE_POS
+/** Increment character position CHAR_POS and byte position UNIT_POS
     so that they point to the next character in M-text MT.  No range
-    check for CHAR_POS and BYTE_POS.  */
+    check for CHAR_POS and UNIT_POS.  */
 
-#define INC_POSITION(mt, char_pos, byte_pos)                   \
+#define INC_POSITION(mt, char_pos, unit_pos)                   \
   do {                                                         \
     int c;                                                     \
                                                                \
-    if ((mt)->format == MTEXT_FORMAT_UTF_8)                    \
+    if ((mt)->format <= MTEXT_FORMAT_UTF_8)                    \
       {                                                                \
-       c = (mt)->data[(byte_pos)];                             \
-       (byte_pos) += CHAR_UNITS_BY_HEAD_UTF8 (c);              \
+       c = (mt)->data[(unit_pos)];                             \
+       (unit_pos) += CHAR_UNITS_BY_HEAD_UTF8 (c);              \
       }                                                                \
-    else                                                       \
+    else if ((mt)->format <= MTEXT_FORMAT_UTF_16BE)            \
       {                                                                \
-       c = ((unsigned short *) ((mt)->data))[(byte_pos)];      \
+       c = ((unsigned short *) ((mt)->data))[(unit_pos)];      \
                                                                \
        if ((mt)->format != default_utf_16)                     \
          c = SWAP_16 (c);                                      \
-       (byte_pos) += (c < 0xD800 || c >= 0xE000) ? 1 : 2;      \
+       (unit_pos) += (c < 0xD800 || c >= 0xE000) ? 1 : 2;      \
       }                                                                \
+    else                                                       \
+      (unit_pos)++;                                            \
     (char_pos)++;                                              \
   } while (0)
 
 
-/** Decrement character position CHAR_POS and byte position BYTE_POS
+/** Decrement character position CHAR_POS and byte position UNIT_POS
     so that they point to the previous character in M-text MT.  No
-    range check for CHAR_POS and BYTE_POS.  */
+    range check for CHAR_POS and UNIT_POS.  */
 
-#define DEC_POSITION(mt, char_pos, byte_pos)                           \
+#define DEC_POSITION(mt, char_pos, unit_pos)                           \
   do {                                                                 \
-    if ((mt)->format == MTEXT_FORMAT_UTF_8)                            \
+    if ((mt)->format <= MTEXT_FORMAT_UTF_8)                            \
       {                                                                        \
-       unsigned char *p1 = (mt)->data + (byte_pos);                    \
+       unsigned char *p1 = (mt)->data + (unit_pos);                    \
        unsigned char *p0 = p1 - 1;                                     \
                                                                        \
        while (! CHAR_HEAD_P (p0)) p0--;                                \
-       (byte_pos) -= (p1 - p0);                                        \
+       (unit_pos) -= (p1 - p0);                                        \
       }                                                                        \
-    else                                                               \
+    else if ((mt)->format <= MTEXT_FORMAT_UTF_16BE)                    \
       {                                                                        \
-       int c = ((unsigned short *) ((mt)->data))[(byte_pos) - 1];      \
+       int c = ((unsigned short *) ((mt)->data))[(unit_pos) - 1];      \
                                                                        \
        if ((mt)->format != default_utf_16)                             \
          c = SWAP_16 (c);                                              \
-       (byte_pos) -= (c < 0xD800 || c >= 0xE000) ? 1 : 2;              \
+       (unit_pos) -= (c < 0xD800 || c >= 0xE000) ? 1 : 2;              \
       }                                                                        \
+    else                                                               \
+      (unit_pos)--;                                                    \
     (char_pos)--;                                                      \
   } while (0)