charcnv: Import push_codepoint().

1 files changed, 61 insertions, 0 deletions

diff --git a/source3/lib/charcnv.c b/source3/lib/charcnv.c
index 374079c8ae..eb794d8347 100644
--- a/source3/lib/charcnv.c
+++ b/source3/lib/charcnv.c
@@ -1861,3 +1861,64 @@ codepoint_t next_codepoint(const char *str, size_t *size)
 	/* no other length is valid */
 	return INVALID_CODEPOINT;
 }
+
+/*
+  push a single codepoint into a CH_UNIX string the target string must
+  be able to hold the full character, which is guaranteed if it is at
+  least 5 bytes in size. The caller may pass less than 5 bytes if they
+  are sure the character will fit (for example, you can assume that
+  uppercase/lowercase of a character will not add more than 1 byte)
+
+  return the number of bytes occupied by the CH_UNIX character, or
+  -1 on failure
+*/
+_PUBLIC_ ssize_t push_codepoint(char *str, codepoint_t c)
+{
+	smb_iconv_t descriptor;
+	uint8_t buf[4];
+	size_t ilen, olen;
+	const char *inbuf;
+	
+	if (c < 128) {
+		*str = c;
+		return 1;
+	}
+
+	lazy_initialize_conv();
+
+	descriptor = conv_handles[CH_UNIX][CH_UTF16LE];
+	if (descriptor == (smb_iconv_t)-1 || descriptor == (smb_iconv_t)0) {
+		return -1;
+	}
+
+	if (c < 0x10000) {
+		ilen = 2;
+		olen = 5;
+		inbuf = (char *)buf;
+		SSVAL(buf, 0, c);
+		smb_iconv(descriptor, &inbuf, &ilen, &str, &olen);
+		if (ilen != 0) {
+			return -1;
+		}
+		return 5 - olen;
+	}
+
+	c -= 0x10000;
+
+	buf[0] = (c>>10) & 0xFF;
+	buf[1] = (c>>18) | 0xd8;
+	buf[2] = c & 0xFF;
+	buf[3] = ((c>>8) & 0x3) | 0xdc;
+
+	ilen = 4;
+	olen = 5;
+	inbuf = (char *)buf;
+
+	smb_iconv(descriptor, &inbuf, &ilen, &str, &olen);
+	if (ilen != 0) {
+		return -1;
+	}
+	return 5 - olen;
+}
+
+