stagit-gopher

commit 05a08e8ab50a8da5b2896c3f5887801d059f48dd
parent a9c90b585f158f98dd0997d1509e83f85dd87498
Author: Hiltjo Posthuma <hiltjo@codemadness.org>
Date:   Sat,  9 Jan 2021 16:19:18 +0100

utf8pad: fix byte-seek issue with negative width codepoints in the range >= 127

For example: "\xef\xbf\xb7" (codepoint 0xfff7), returns wcwidth(wc) == -1.
The next byte was incorrected seeked, but the codepoint itself was valid
(mbtowc).

Diffstat:
M
stagit-gopher-index.c
 | 
7
+++----
M
stagit-gopher.c
 | 
7
+++----

2 files changed, 6 insertions(+), 8 deletions(-)
diff --git a/stagit-gopher-index.c b/stagit-gopher-index.c
@@ -38,19 +38,18 @@ utf8pad(char *buf, size_t bufsiz, const char *s, size_t len, int pad)
 
 	slen = strlen(s);
 	for (i = 0; i < slen; i += inc) {
-		inc = 1;
+		inc = 1; /* next byte */
 		if ((unsigned char)s[i] < 32)
 			continue;
 
 		rl = mbtowc(&wc, &s[i], slen - i < 4 ? slen - i : 4);
+		inc = rl;
 		if (rl < 0) {
 			mbtowc(NULL, NULL, 0); /* reset state */
-			inc = 1; /* next byte */
+			inc = 1; /* invalid, seek next byte */
 			w = 1; /* replacement char is one width */
 		} else if ((w = wcwidth(wc)) == -1) {
 			continue;
-		} else {
-			inc = rl;
 		}
 
 		if (col + w > len || (col + w == len && s[i + inc])) {
diff --git a/stagit-gopher.c b/stagit-gopher.c
@@ -100,19 +100,18 @@ utf8pad(char *buf, size_t bufsiz, const char *s, size_t len, int pad)
 
 	slen = strlen(s);
 	for (i = 0; i < slen; i += inc) {
-		inc = 1;
+		inc = 1; /* next byte */
 		if ((unsigned char)s[i] < 32)
 			continue;
 
 		rl = mbtowc(&wc, &s[i], slen - i < 4 ? slen - i : 4);
+		inc = rl;
 		if (rl < 0) {
 			mbtowc(NULL, NULL, 0); /* reset state */
-			inc = 1; /* next byte */
+			inc = 1; /* invalid, seek next byte */
 			w = 1; /* replacement char is one width */
 		} else if ((w = wcwidth(wc)) == -1) {
 			continue;
-		} else {
-			inc = rl;
 		}
 
 		if (col + w > len || (col + w == len && s[i + inc])) {