/(?i)\u0149\u0149/ =~ "\u0149\u0149" doesn't match (Issue #40)

'\u0149' is casefolded into '\u02bc' + 'n'.  They were compiled into
'exactn-ic:\xca\xbc' + 'exact1-ic:n'.  One character was divided into
two opcodes, so it couldn't match to a character '\u0149'.
Merge a series of 'exactn-ic' and 'exact1-ic' into one 'exactn-ic'.
(cherry picked from commit 7b61f4b)

Conflicts:

	regcomp.c

regcomp.c

@@ -312,9 +312,10 @@ static int compile_tree(Node* node, regex_t* reg);
     (op) == OP_EXACTMB3N || (op) == OP_EXACTMBN  || (op) == OP_EXACTN_IC)
 
 static int
-select_str_opcode(int mb_len, int str_len, int ignore_case)
+select_str_opcode(int mb_len, int byte_len, int ignore_case)
 {
   int op;
+  OnigDistance str_len = (byte_len + mb_len - 1) / mb_len;
 
   if (ignore_case) {
     switch (str_len) {
@@ -416,48 +417,48 @@ compile_tree_n_times(Node* node, int n, regex_t* reg)
 }
 
 static int
-add_compile_string_length(UChar* s ARG_UNUSED, int mb_len, int str_len,
+add_compile_string_length(UChar* s ARG_UNUSED, int mb_len, int byte_len,
                           regex_t* reg ARG_UNUSED, int ignore_case)
 {
   int len;
-  int op = select_str_opcode(mb_len, str_len, ignore_case);
+  int op = select_str_opcode(mb_len, byte_len, ignore_case);
 
   len = SIZE_OPCODE;
 
   if (op == OP_EXACTMBN)  len += SIZE_LENGTH;
   if (IS_NEED_STR_LEN_OP_EXACT(op))
     len += SIZE_LENGTH;
 
-  len += mb_len * str_len;
+  len += byte_len;
   return len;
 }
 
 static int
-add_compile_string(UChar* s, int mb_len, int str_len,
+add_compile_string(UChar* s, int mb_len, int byte_len,
                    regex_t* reg, int ignore_case)
 {
-  int op = select_str_opcode(mb_len, str_len, ignore_case);
+  int op = select_str_opcode(mb_len, byte_len, ignore_case);
   add_opcode(reg, op);
 
   if (op == OP_EXACTMBN)
     add_length(reg, mb_len);
 
   if (IS_NEED_STR_LEN_OP_EXACT(op)) {
     if (op == OP_EXACTN_IC)
-      add_length(reg, mb_len * str_len);
+      add_length(reg, byte_len);
     else
-      add_length(reg, str_len);
+      add_length(reg, byte_len / mb_len);
   }
 
-  add_bytes(reg, s, mb_len * str_len);
+  add_bytes(reg, s, byte_len);
   return 0;
 }
 
 
 static int
 compile_length_string_node(Node* node, regex_t* reg)
 {
-  int rlen, r, len, prev_len, slen, ambig;
+  int rlen, r, len, prev_len, blen, ambig;
   OnigEncoding enc = reg->enc;
   UChar *p, *prev;
   StrNode* sn;
@@ -471,24 +472,24 @@ compile_length_string_node(Node* node, regex_t* reg)
   p = prev = sn->s;
   prev_len = enclen(enc, p);
   p += prev_len;
-  slen = 1;
+  blen = prev_len;
   rlen = 0;
 
   for (; p < sn->end; ) {
     len = enclen(enc, p);
-    if (len == prev_len) {
-      slen++;
+    if (len == prev_len || ambig) {
+      blen += len;
     }
     else {
-      r = add_compile_string_length(prev, prev_len, slen, reg, ambig);
+      r = add_compile_string_length(prev, prev_len, blen, reg, ambig);
       rlen += r;
       prev = p;
-      slen = 1;
+      blen = len;
       prev_len = len;
     }
     p += len;
   }
-  r = add_compile_string_length(prev, prev_len, slen, reg, ambig);
+  r = add_compile_string_length(prev, prev_len, blen, reg, ambig);
   rlen += r;
   return rlen;
 }
@@ -505,7 +506,7 @@ compile_length_string_raw_node(StrNode* sn, regex_t* reg)
 static int
 compile_string_node(Node* node, regex_t* reg)
 {
-  int r, len, prev_len, slen, ambig;
+  int r, len, prev_len, blen, ambig;
   OnigEncoding enc = reg->enc;
   UChar *p, *prev, *end;
   StrNode* sn;
@@ -520,25 +521,25 @@ compile_string_node(Node* node, regex_t* reg)
   p = prev = sn->s;
   prev_len = enclen(enc, p);
   p += prev_len;
-  slen = 1;
+  blen = prev_len;
 
   for (; p < end; ) {
     len = enclen(enc, p);
-    if (len == prev_len) {
-      slen++;
+    if (len == prev_len || ambig) {
+      blen += len;
     }
     else {
-      r = add_compile_string(prev, prev_len, slen, reg, ambig);
+      r = add_compile_string(prev, prev_len, blen, reg, ambig);
       if (r) return r;
 
       prev  = p;
-      slen  = 1;
+      blen  = len;
       prev_len = len;
     }
 
     p += len;
   }
-  return add_compile_string(prev, prev_len, slen, reg, ambig);
+  return add_compile_string(prev, prev_len, blen, reg, ambig);
 }
 
 static int