Give iconvbufs() an ICB_INIT flag.

flist.c

@@ -731,7 +731,7 @@ static struct file_struct *recv_file_entry(int f, struct file_list *flist, int x
 		INIT_CONST_XBUF(outbuf, thisname);
 		INIT_XBUF(inbuf, lastname, basename_len, (size_t)-1);
 
-		if (iconvbufs(ic_recv, &inbuf, &outbuf, 0) < 0) {
+		if (iconvbufs(ic_recv, &inbuf, &outbuf, ICB_INIT) < 0) {
 			io_error |= IOERR_GENERAL;
 			rprintf(FERROR_UTF8,
 			    "[%s] cannot convert filename: %s (%s)\n",
@@ -1049,7 +1049,7 @@ static struct file_struct *recv_file_entry(int f, struct file_list *flist, int x
 				read_sbuf(f, inbuf.buf, inbuf.len);
 				INIT_XBUF(outbuf, bp, 0, alloc_len);
 
-				if (iconvbufs(ic_recv, &inbuf, &outbuf, 0) < 0) {
+				if (iconvbufs(ic_recv, &inbuf, &outbuf, ICB_INIT) < 0) {
 					io_error |= IOERR_GENERAL;
 					rprintf(FERROR_XFER,
 					    "[%s] cannot convert symlink data for: %s (%s)\n",
@@ -1464,14 +1464,14 @@ static struct file_struct *send_file_name(int f, struct file_list *flist,
 			if (file->dirname) {
 				INIT_XBUF_STRLEN(inbuf, (char*)file->dirname);
 				outbuf.size -= 2; /* Reserve room for '/' & 1 more char. */
-				if (iconvbufs(ic_send, &inbuf, &outbuf, 0) < 0)
+				if (iconvbufs(ic_send, &inbuf, &outbuf, ICB_INIT) < 0)
 					goto convert_error;
 				outbuf.size += 2;
 				fbuf[outbuf.len++] = '/';
 			}
 
 			INIT_XBUF_STRLEN(inbuf, (char*)file->basename);
-			if (iconvbufs(ic_send, &inbuf, &outbuf, 0) < 0) {
+			if (iconvbufs(ic_send, &inbuf, &outbuf, ICB_INIT) < 0) {
 			  convert_error:
 				io_error |= IOERR_GENERAL;
 				rprintf(FERROR_XFER,
@@ -1485,7 +1485,7 @@ static struct file_struct *send_file_name(int f, struct file_list *flist,
 			if (symlink_len && sender_symlink_iconv) {
 				INIT_XBUF(inbuf, (char*)symlink_name, symlink_len, (size_t)-1);
 				INIT_CONST_XBUF(outbuf, symlink_buf);
-				if (iconvbufs(ic_send, &inbuf, &outbuf, 0) < 0) {
+				if (iconvbufs(ic_send, &inbuf, &outbuf, ICB_INIT) < 0) {
 					io_error |= IOERR_GENERAL;
 					f_name(file, fbuf);
 					rprintf(FERROR_XFER,

io.c

@@ -378,7 +378,7 @@ static void forward_filesfrom_data(void)
 	}
 	if (len) {
 		char *f = x.buf + x.pos;
-		char *t = f; /* Keep any non-zero offset to avoid iconv reset. */
+		char *t = x.buf;
 		char *eob = f + len;
 		/* Eliminate any multi-'\0' runs. */
 		while (f != eob) {
@@ -393,7 +393,7 @@ static void forward_filesfrom_data(void)
 	if (filesfrom_convert) {
 		/* TODO would it help to translate each string between nulls separately? */
 		x.len = len;
-		iconvbufs(ic_send, &x, &iobuf.out, ICB_INCLUDE_BAD|ICB_INCLUDE_INCOMPLETE|ICB_CIRCULAR_OUT);
+		iconvbufs(ic_send, &x, &iobuf.out, ICB_INCLUDE_BAD|ICB_INCLUDE_INCOMPLETE|ICB_CIRCULAR_OUT|ICB_INIT);
 	} else
 #endif
 	if (len) {
@@ -803,7 +803,7 @@ int send_msg(enum msgcode code, const char *buf, size_t len, int convert)
 
 		len = iobuf.msg.len;
 		iconvbufs(ic_send, &inbuf, &iobuf.msg,
-			  ICB_INCLUDE_BAD | ICB_INCLUDE_INCOMPLETE | ICB_CIRCULAR_OUT);
+			  ICB_INCLUDE_BAD | ICB_INCLUDE_INCOMPLETE | ICB_CIRCULAR_OUT | ICB_INIT);
 		if (inbuf.len > 0) {
 			rprintf(FERROR, "overflowed iobuf.msg buffer in send_msg");
 			exit_cleanup(RERR_UNSUPPORTED);
@@ -1039,7 +1039,7 @@ int read_line(int fd, char *buf, size_t bufsiz, int flags)
 		iconv_buf.pos = 0;
 		iconv_buf.len = s - iconv_buf.buf;
 		iconvbufs(ic_recv, &iconv_buf, &outbuf,
-			  ICB_INCLUDE_BAD | ICB_INCLUDE_INCOMPLETE);
+			  ICB_INCLUDE_BAD | ICB_INCLUDE_INCOMPLETE | ICB_INIT);
 		outbuf.buf[outbuf.len] = '\0';
 		return outbuf.len;
 	}
@@ -1301,13 +1301,14 @@ static void read_a_msg(void)
 			INIT_XBUF(inbuf, ibuf, 0, (size_t)-1);
 
 			while (msg_bytes) {
+				inbuf.pos = 0;
 				inbuf.len = msg_bytes > sizeof ibuf ? sizeof ibuf : msg_bytes;
 				memcpy(inbuf.buf, perform_io(inbuf.len, PIO_INPUT_AND_CONSUME), inbuf.len);
 				if (!(msg_bytes -= inbuf.len)
 				 && !ibuf[inbuf.len-1])
 					inbuf.len--, add_null = 1;
 				if (iconvbufs(ic_send, &inbuf, &outbuf,
-				    ICB_INCLUDE_BAD | ICB_INCLUDE_INCOMPLETE) < 0)
+				    ICB_INCLUDE_BAD | ICB_INCLUDE_INCOMPLETE | ICB_INIT) < 0)
 					goto overflow;
 			}
 			if (add_null) {

log.c

@@ -359,7 +359,7 @@ output_msg:
 		INIT_XBUF(inbuf, (char*)buf, len, (size_t)-1);
 
 		while (inbuf.len) {
-			iconvbufs(ic, &inbuf, &outbuf, 0);
+			iconvbufs(ic, &inbuf, &outbuf, inbuf.pos ? 0 : ICB_INIT);
 			ierrno = errno;
 			if (outbuf.len) {
 				filtered_fwrite(f, convbuf, outbuf.len, 0);

rsync.c

@@ -160,8 +160,8 @@ static void wrap_overflow(xbuf *out, int siz)
  * "flags", any badly-encoded chars are included verbatim in the "out" xbuf,
  * so EILSEQ will not be returned.  Likewise for ICB_INCLUDE_INCOMPLETE with
  * respect to an incomplete multi-byte char at the end, which ensures that
- * EINVAL is not returned.  Anytime "in.pos" is 0 we will reset the iconv()
- * state prior to processing the characters. */
+ * EINVAL is not returned.  If ICB_INIT is set, the iconv() conversion state
+ * is initialized prior to processing the characters. */
 int iconvbufs(iconv_t ic, xbuf *in, xbuf *out, int flags)
 {
 	ICONV_CONST char *ibuf;
@@ -171,7 +171,7 @@ int iconvbufs(iconv_t ic, xbuf *in, xbuf *out, int flags)
 	if (!out->size && flags & ICB_EXPAND_OUT)
 		alloc_xbuf(out, 1024);
 
-	if (!in->pos)
+	if (flags & ICB_INIT)
 		iconv(ic, NULL, 0, NULL, 0);
 
 	ibuf = in->buf + in->pos;
@@ -265,7 +265,7 @@ void send_protected_args(int fd, char *args[])
 		else if (convert) {
 			INIT_XBUF_STRLEN(inbuf, args[i]);
 			iconvbufs(ic_send, &inbuf, &outbuf,
-				  ICB_EXPAND_OUT | ICB_INCLUDE_BAD | ICB_INCLUDE_INCOMPLETE);
+				  ICB_EXPAND_OUT | ICB_INCLUDE_BAD | ICB_INCLUDE_INCOMPLETE | ICB_INIT);
 			outbuf.buf[outbuf.len] = '\0';
 			write_buf(fd, outbuf.buf, outbuf.len + 1);
 			outbuf.len = 0;

rsync.h

@@ -901,6 +901,7 @@ typedef struct {
 #define ICB_INCLUDE_BAD (1<<1)
 #define ICB_INCLUDE_INCOMPLETE (1<<2)
 #define ICB_CIRCULAR_OUT (1<<3)
+#define ICB_INIT (1<<4)
 
 #define RL_EOL_NULLS (1<<0)
 #define RL_DUMP_COMMENTS (1<<1)