[PATCH BlueZ v3 1/7] shared/util: Add strtoutf8 function

["Frédéric Danis" <frederic.danis@collabora.com>]

This adds the strtoutf8 function that truncate a string before the
first non UTF-8 character.
This truncation is done in place.
---
 src/shared/util.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 src/shared/util.h |  1 +
 2 files changed, 43 insertions(+)

diff --git a/src/shared/util.c b/src/shared/util.c
index 5d3a14d96..5262458cb 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -1959,3 +1959,45 @@ bool argsisutf8(int argc, char *argv[])
 
 	return true;
 }
+
+char *strtoutf8(char *str, size_t len)
+{
+	size_t i = 0;
+
+	while (i < len) {
+		unsigned char c = str[i];
+		size_t size = 0;
+
+		/* Check the first byte to determine the number of bytes in the
+		 * UTF-8 character.
+		 */
+		if ((c & 0x80) == 0x00)
+			size = 1;
+		else if ((c & 0xE0) == 0xC0)
+			size = 2;
+		else if ((c & 0xF0) == 0xE0)
+			size = 3;
+		else if ((c & 0xF8) == 0xF0)
+			size = 4;
+		else
+			/* Invalid UTF-8 sequence */
+			goto done;
+
+		/* Check the following bytes to ensure they have the correct
+		 * format.
+		 */
+		for (size_t j = 1; j < size; ++j) {
+			if (i + j > len || (str[i + j] & 0xC0) != 0x80)
+				/* Invalid UTF-8 sequence */
+				goto done;
+		}
+
+		/* Move to the next character */
+		i += size;
+	}
+
+done:
+	/* Truncate to the longest valid UTF-8 string */
+	memset(str + i, 0, len - i);
+	return str;
+}
diff --git a/src/shared/util.h b/src/shared/util.h
index dd357fb93..6fc02a9dc 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -92,6 +92,7 @@ int strsuffix(const char *str, const char *suffix);
 char *strstrip(char *str);
 bool strisutf8(const char *str, size_t length);
 bool argsisutf8(int argc, char *argv[]);
+char *strtoutf8(char *str, size_t len);
 
 void *util_malloc(size_t size);
 void *util_memdup(const void *src, size_t size);
-- 
2.43.0