Attachment 179126 Details for Bug 195763 – Proposed patch to address zero length match issues with bsdgrep

[patch] Proposed patch to address zero length match issues with bsdgrep

grep-zerolen.patch (text/plain), 2.56 KB, created by Kyle Evans on 2017-01-20 06:27:46 UTC

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Creator: Kyle Evans

Created: 2017-01-20 06:27:46 UTC

Size: 2.56 KB

patch

obsolete

>diff --git a/usr.bin/grep/grep.c b/usr.bin/grep/grep.c
>index b744b8aab8a..81b0ffae67a 100644
>--- a/usr.bin/grep/grep.c
>+++ b/usr.bin/grep/grep.c
>@@ -339,7 +339,7 @@ main(int argc, char *argv[])
> 	const char *pn;
> 	unsigned long long l;
> 	unsigned int aargc, eargc, i;
>-	int c, lastc, needpattern, newarg, prevoptind;
>+	int c, lastc, needpattern, newarg, prevoptind, pofs;
> 
> 	setlocale(LC_ALL, "");
> 
>@@ -704,18 +704,23 @@ main(int argc, char *argv[])
> 
> 	fg_pattern = grep_calloc(patterns, sizeof(*fg_pattern));
> 	r_pattern = grep_calloc(patterns, sizeof(*r_pattern));
>+	pofs = 0;
> 
> 	/* Check if cheating is allowed (always is for fgrep). */
> 	for (i = 0; i < patterns; ++i) {
>-		if (fastncomp(&fg_pattern[i], pattern[i].pat,
>+		if (fastncomp(&fg_pattern[i - pofs], pattern[i].pat,
> 		    pattern[i].len, cflags) != 0) {
> 			/* Fall back to full regex library */
>-			c = regcomp(&r_pattern[i], pattern[i].pat, cflags);
>+			c = regcomp(&r_pattern[i - pofs], pattern[i].pat, cflags);
> 			if (c != 0) {
>-				regerror(c, &r_pattern[i], re_error,
>+				regerror(c, &r_pattern[i - pofs], re_error,
> 				    RE_ERROR_BUF);
> 				errx(2, "%s", re_error);
> 			}
>+		} else {
>+			/* Deduct one for invalid pattern */
>+			patterns --;
>+			pofs ++;
> 		}
> 	}
> 
>diff --git a/usr.bin/grep/util.c b/usr.bin/grep/util.c
>index fa1a967463f..24453d7c1b4 100644
>--- a/usr.bin/grep/util.c
>+++ b/usr.bin/grep/util.c
>@@ -294,13 +294,13 @@ procline(struct str *l, int nottext)
> 	regmatch_t pmatch;
> 	size_t st = 0;
> 	unsigned int i;
>-	int c = 0, m = 0, r = 0;
>+	int c = 0, m = 0, r = 0, lastmatches = 0;
> 
> 	/* Loop to process the whole line */
> 	while (st <= l->len) {
> 		pmatch.rm_so = st;
> 		pmatch.rm_eo = l->len;
>-
>+		lastmatches = 0;
> 		/* Loop to compare with all the patterns */
> 		for (i = 0; i < patterns; i++) {
> 			if (fg_pattern[i].pattern)
>@@ -339,10 +339,16 @@ procline(struct str *l, int nottext)
> 					r = REG_NOMATCH;
> 			}
> 			if (r == 0) {
>+				lastmatches ++;
>+				/* Skip over zero-length matches */
>+				if (pmatch.rm_so == pmatch.rm_eo)
>+					continue;
> 				if (m == 0)
> 					c++;
>-				if (m < MAX_LINE_MATCHES)
>+				if (m < MAX_LINE_MATCHES) {
> 					matches[m++] = pmatch;
>+				}
>+
> 				/* matches - skip further patterns */
> 				if ((color == NULL && !oflag) ||
> 				    qflag || lflag)
>@@ -359,8 +365,10 @@ procline(struct str *l, int nottext)
> 		if (!wflag && ((color == NULL && !oflag) || qflag || lflag || Lflag))
> 			break;
> 
>-		if (st == (size_t)pmatch.rm_so)
>+		if (lastmatches == 0)
> 			break; 	/* No matches */
>+		else if (st == (size_t)pmatch.rm_so)
>+			st ++;	/* Zero-length match -- advance one more */
> 	}
> 
>

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