Correctly account the number of bytes processed when outputting UTF-8 encoded

characters.

2 files changed, 20 insertions, 17 deletions

diff --git a/sys/dev/wscons/wsemul_sun.c b/sys/dev/wscons/wsemul_sun.c
index c866b11eed7..40871af462b 100644
--- a/sys/dev/wscons/wsemul_sun.c
+++ b/sys/dev/wscons/wsemul_sun.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: wsemul_sun.c,v 1.35 2023/03/06 17:14:44 miod Exp $ */
+/* $OpenBSD: wsemul_sun.c,v 1.36 2023/03/06 20:34:35 miod Exp $ */
 /* $NetBSD: wsemul_sun.c,v 1.11 2000/01/05 11:19:36 drochner Exp $ */
 
 /*
@@ -662,7 +662,7 @@ wsemul_sun_output(void *cookie, const u_char *data, u_int count, int kernel)
 {
 	struct wsemul_sun_emuldata *edp = cookie;
 	struct wsemul_inputstate *instate;
-	u_int processed = 0;
+	u_int prev_count, processed = 0;
 #ifdef HAVE_JUMP_SCROLL
 	int lines;
 #endif
@@ -679,7 +679,7 @@ wsemul_sun_output(void *cookie, const u_char *data, u_int count, int kernel)
 	case ABORT_FAILED_CURSOR:
 		/*
 		 * If we could not display the cursor back, we pretended not
-		 * having been able to display the last character. But this
+		 * having been able to process the last byte. But this
 		 * is a lie, so compensate here.
 		 */
 		data++, count--;
@@ -746,6 +746,7 @@ wsemul_sun_output(void *cookie, const u_char *data, u_int count, int kernel)
 
 		wsemul_resume_abort(&edp->abortstate);
 
+		prev_count = count;
 		if (wsemul_getchar(&data, &count, instate,
 #ifdef HAVE_UTF8_SUPPORT
 		    (edp->state == SUN_EMUL_STATE_NORMAL && !kernel) ?
@@ -760,7 +761,7 @@ wsemul_sun_output(void *cookie, const u_char *data, u_int count, int kernel)
 			rc = wsemul_sun_output_lowchars(edp, instate, kernel);
 			if (rc != 0)
 				break;
-			processed++;
+			processed += prev_count - count;
 			continue;
 		}
 
@@ -768,7 +769,7 @@ wsemul_sun_output(void *cookie, const u_char *data, u_int count, int kernel)
 			rc = wsemul_sun_output_normal(edp, instate, 1);
 			if (rc != 0)
 				break;
-			processed++;
+			processed += prev_count - count;
 			continue;
 		}
 
@@ -799,7 +800,7 @@ wsemul_sun_output(void *cookie, const u_char *data, u_int count, int kernel)
 		}
 		if (rc != 0)
 			break;
-		processed++;
+		processed += prev_count - count;
 	}
 
 	if (rc != 0)
@@ -810,8 +811,9 @@ wsemul_sun_output(void *cookie, const u_char *data, u_int count, int kernel)
 		    (edp->emulcookie, 1, edp->crow, edp->ccol);
 		if (rc != 0) {
 			/*
-			 * Fail the last character output, remembering that
-			 * only the cursor operation really needs to be done.
+			 * Pretend the last byte hasn't been processed, while
+			 * remembering that only the cursor operation really
+			 * needs to be done.
 			 */
 			wsemul_abort_cursor(&edp->abortstate);
 			processed--;
diff --git a/sys/dev/wscons/wsemul_vt100.c b/sys/dev/wscons/wsemul_vt100.c
index b58f2237dd8..1f976bd8231 100644
--- a/sys/dev/wscons/wsemul_vt100.c
+++ b/sys/dev/wscons/wsemul_vt100.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: wsemul_vt100.c,v 1.44 2023/03/06 17:14:44 miod Exp $ */
+/* $OpenBSD: wsemul_vt100.c,v 1.45 2023/03/06 20:34:35 miod Exp $ */
 /* $NetBSD: wsemul_vt100.c,v 1.13 2000/04/28 21:56:16 mycroft Exp $ */
 
 /*
@@ -1110,7 +1110,7 @@ wsemul_vt100_output(void *cookie, const u_char *data, u_int count, int kernel)
 {
 	struct wsemul_vt100_emuldata *edp = cookie;
 	struct wsemul_inputstate *instate;
-	u_int processed = 0;
+	u_int prev_count, processed = 0;
 #ifdef HAVE_JUMP_SCROLL
 	int lines;
 #endif
@@ -1127,7 +1127,7 @@ wsemul_vt100_output(void *cookie, const u_char *data, u_int count, int kernel)
 	case ABORT_FAILED_CURSOR:
 		/*
 		 * If we could not display the cursor back, we pretended not
-		 * having been able to display the last character. But this
+		 * having been able to process the last byte. But this
 		 * is a lie, so compensate here.
 		 */
 		data++, count--;
@@ -1200,6 +1200,7 @@ wsemul_vt100_output(void *cookie, const u_char *data, u_int count, int kernel)
 
 		wsemul_resume_abort(&edp->abortstate);
 
+		prev_count = count;
 		if (wsemul_getchar(&data, &count, instate,
 #ifdef HAVE_UTF8_SUPPORT
 		    (edp->state == VT100_EMUL_STATE_NORMAL && !kernel) ?
@@ -1215,7 +1216,7 @@ wsemul_vt100_output(void *cookie, const u_char *data, u_int count, int kernel)
 			rc = wsemul_vt100_output_c0c1(edp, instate, kernel);
 			if (rc != 0)
 				break;
-			processed++;
+			processed += prev_count - count;
  			continue;
  		}
 
@@ -1223,7 +1224,7 @@ wsemul_vt100_output(void *cookie, const u_char *data, u_int count, int kernel)
 			rc = wsemul_vt100_output_normal(edp, instate, kernel);
 			if (rc != 0)
 				break;
-			processed++;
+			processed += prev_count - count;
 			continue;
 		}
 #ifdef DIAGNOSTIC
@@ -1233,7 +1234,7 @@ wsemul_vt100_output(void *cookie, const u_char *data, u_int count, int kernel)
 		rc = vt100_output[edp->state - 1](edp, instate);
 		if (rc != 0)
 			break;
-		processed++;
+		processed += prev_count - count;
 	}
 
 	if (rc != 0)
@@ -1250,9 +1251,9 @@ wsemul_vt100_output(void *cookie, const u_char *data, u_int count, int kernel)
 #endif
 			if (rc != 0) {
 				/*
-				 * Fail the last character output, remembering
-				 * that only the cursor operation really needs
-				 * to be done.
+				 * Pretend the last byte hasn't been processed,
+				 * while remembering that only the cursor
+				 * operation really needs to be done.
 				 */
 				wsemul_abort_cursor(&edp->abortstate);
 				processed--;