58586: print "%s" with invalid multibyte character

Treat each byte that is invalid or part of an incopmlete set as a single byte.

ChangeLog

@@ -1,3 +1,9 @@
+2023-03-22  Peter Stephenson  <p.stephenson@samsung.com>
+
+	* 51586: Src/builtin.c: When printf "%s" encounters a byte
+	that's not part of a vaild multibyte character it should handle
+	it a single byte at a time.
+
 2023-03-16  Oliver Kiddle  <opk@zsh.org>
 
 	* 51583: Completion/Unix/Command/_git: update completion of

Src/builtin.c

@@ -5329,20 +5329,21 @@ bin_print(char *name, char **args, Options ops, int func)
 #ifdef MULTIBYTE_SUPPORT
 			if (isset(MULTIBYTE)) {
 			    chars = mbrlen(ptr, lleft, &mbs);
-			    if (chars < 0) {
+			    /*
-				/*
+			     * chars <= 0 means one of
-				 * Invalid/incomplete character at this
+			     *
-				 * point.  Assume all the rest are a
+			     * 0: NUL, handle as real character
-				 * single byte.  That's about the best we
+			     *
-				 * can do.
+			     * -1: MB_INVALID: Assume this is
-				 */
+			     *     a single character as we do
-				lchars += lleft;
+			     *     elsewhere in the code.
-				lbytes = (ptr - b) + lleft;
+			     *
-				break;
+			     * -2: MB_INCOMPLETE: We're not waiting
-			    } else if (chars == 0) {
+			     *     for input on this occasion, so
-				/* NUL, handle as real character */
+			     *     just treat this as invalid.
+			     */
+			    if (chars <= 0)
 				chars = 1;
-			    }
 			}
 			else	/* use the non-multibyte code below */
 #endif