openbsd-ports/comms/jpilot/patches/patch-japanese_c

$OpenBSD: patch-japanese_c,v 1.1.1.1 2001/05/29 00:54:44 pvalchev Exp $
--- japanese.c.orig	Wed Jan 31 09:51:33 2001
+++ japanese.c	Sun May 27 17:12:01 2001
@@ -10,7 +10,7 @@
 
 #include <stdlib.h>
 #include <stdio.h>
-
+ 
 /* In utils.c, also a prototype in utils.h */
 void multibyte_safe_strncpy(char *dst, char *src, size_t max_len);
 
@@ -23,7 +23,14 @@ void multibyte_safe_strncpy(char *dst, c
 #define isEuc(c) \
     (0xa0 < ((unsigned char) (c)) && ((unsigned char) (c)) < 0xff)
 
+/* convert SJIS char to EUC char 
+
+   this does not support Machine dependent codes.
+   args: hi: first byte of sjis char.
+         lo: second byte of sjis char.
+   return:   euc char in 16bit value. 
 
+ */
 static unsigned int SjisToEuc(unsigned char hi, unsigned char lo)
 {
   if (lo >= 0x9f)
@@ -33,7 +40,11 @@ static unsigned int SjisToEuc(unsigned c
             (lo + (lo >= 0x7f ? 0x60 : 0x61));
 }
 
-
+/* 
+   args: source char pointer, destination source pointer, a length of srting
+   Length include null termination.  
+   return the pointer of nul termination code.
+ */
 unsigned char *Sjis2EucCpy(unsigned char *dest, unsigned char *src, int max_len)
 {
     unsigned char *p, *q;
@@ -43,8 +54,8 @@ unsigned char *Sjis2EucCpy(unsigned char
 
     p = src;
     q = dest;
-    while ((*p) && (n < max_len-1)) {
-	    if (isSjis1stByte(*p)) {
+    while ((*p) && (n < max_len-2)) {
+        if (isSjis1stByte(*p)) {
   	    hi = *p++;
 	    lo = *p++;
 	    w = SjisToEuc(hi, lo);
@@ -58,27 +69,48 @@ unsigned char *Sjis2EucCpy(unsigned char
 	} else if ((*p) & 0x80) {	            /* irregular japanese char */
 	    p++;                                    /* ??abort and return NULL?? */
 	    /* discard it */ 
-	    } else {
+	} else {
 	    *q++ = *p++;
 	    n++;
 	}
     }
-    *q = '\0';
-    return dest;
+    if ((*p) && !(*p & 0x80) && (n < max_len-1)) {
+	    *q++ = *p++;
+	    *q = '\0';
+    } else {
+	    *q = '\0';
+    }
+    return q;
 }
 
+/* 
+   convert strings from Sjis to EUC.
+   max_len includes null termiantion.
+   size of buf must be more than max_len.
+
+*/
+
 void Sjis2Euc(unsigned char *buf, int max_len)
 {
 	unsigned char *dst;
 
 	if (buf == NULL) return;
-	if ((dst = (unsigned char *)malloc(max_len*2)) != NULL) {
-		if (Sjis2EucCpy(dst, buf, max_len*2) != NULL)
+	if ((dst = (unsigned char *)malloc(max_len)) != NULL) { 
+                            /* assign buffer for destination. */
+		if (Sjis2EucCpy(dst, buf, max_len) != NULL) { 
 			multibyte_safe_strncpy(buf, dst, max_len);
+			buf[max_len-1] = '\0';  /* i am a paranoire B-) */
+		}
 		free(dst);
-    }
+	}
 }
 
+/*
+   Convert one char from euc to sjis.
+   args:  hi:  first byte of euc code.
+          lo:  second byte of euc code.
+   return:  16bit value of sjis char code. 
+ */
 static unsigned int EucToSjis(unsigned char hi, unsigned char lo)
 {
   if (hi & 1)
@@ -88,6 +120,11 @@ static unsigned int EucToSjis(unsigned c
     return ((hi / 2 + (hi < 0xdf ? 0x30 : 0x70)) << 8) | (lo - 2);
 }
 
+/* 
+   Convert string from euc to sjis with coping to another buffer. 
+   Theoritically, strlen(EUC) >= strlen(SJIS), 
+    then it is ok that dest == src.
+ */
 unsigned char *Euc2SjisCpy(unsigned char *dest, unsigned char *src, int max_len)
 {
     unsigned char *p, *q; 
@@ -97,7 +134,7 @@ unsigned char *Euc2SjisCpy(unsigned char
 
     p = src;   
     q = dest;
-    while ((*p) && (n < max_len-1)) {
+    while ((*p) && (n < max_len-2)) {
 	if (isEucKana(*p)) {      /* euc kana(2byte) -> sjis(1byte) */
 	    p++;
 	    *q++ = *p++;
@@ -114,12 +151,24 @@ unsigned char *Euc2SjisCpy(unsigned char
 	    n++;
 	}
     }
-    *q = '\0';
+    if ((*p) && !(*p & 0x80) && n < max_len-1) {
+	    *q++ = *p++;
+	    *q = '\0';
+    } else {
+	    *q = '\0';
+    }
     return dest;
 }
+/*
+  convert euc to sjis.
+  size of buf must be more than man_len.
+  it simply call Euc2SjisCpy().
+  this function exists for symmetry.
+ */
 
 void Euc2Sjis(unsigned char *buf, int max_len)
 {
 	if (buf == NULL) return;
-	Euc2SjisCpy(buf, buf, max_len);
+	if (max_len <= 0) return;
+	(void *)Euc2SjisCpy(buf, buf, max_len);
 }