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[PATCH v5 05/10] grep/icase: avoid kwsset when -F is specified

From
Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Date
Jan 28, 2016, 11:56 UTC
Message-ID
<1453982183-24124-6-git-send-email-pclouds@gmail.com>
In-Reply-To
<1453982183-24124-1-git-send-email-pclouds@gmail.com>

Similar to the previous commit, we can't use kws on icase search outside ascii range. But we can't simply pass the pattern to regcomp/pcre like the previous commit because it may contain regex special characters, so we need to quote the regex first.

To avoid misquote traps that could lead to undefined behavior, we always stick to basic regex engine in this case. We don't need fancy features for grepping a literal string anyway.

basic_regex_quote_buf() assumes that if the pattern is in a multibyte encoding, ascii chars must be unambiguously encoded as single bytes. This is true at least for UTF-8. For others, let's wait until people yell up. Chances are nobody uses multibyte, non utf-8 charsets any more..

Helped-by: René Scharfe <l.s.r@web.de>
Noticed-by: Plamen Totev <plamen.totev@abv.bg>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 grep.c                          | 25 ++++++++++++++++++++++++-
 quote.c                         | 37 +++++++++++++++++++++++++++++++++++++
 quote.h                         |  1 +
 t/t7812-grep-icase-non-ascii.sh | 26 ++++++++++++++++++++++++++
 4 files changed, 88 insertions(+), 1 deletion(-)
diff --git a/grep.c b/grep.c
index f2180a2..fa96a29 100644
--- a/grep.c
+++ b/grep.c
@@ -5,6 +5,7 @@
 #include "diff.h"
 #include "diffcore.h"
 #include "commit.h"
+#include "quote.h"
 
 static int grep_source_load(struct grep_source *gs);
 static int grep_source_is_binary(struct grep_source *gs);
@@ -397,6 +398,24 @@ static int is_fixed(const char *s, size_t len)
 	return 1;
 }
 
+static void compile_fixed_regexp(struct grep_pat *p, struct grep_opt *opt)
+{
+	struct strbuf sb = STRBUF_INIT;
+	int err;
+
+	basic_regex_quote_buf(&sb, p->pattern);
+	err = regcomp(&p->regexp, sb.buf, opt->regflags & ~REG_EXTENDED);
+	if (opt->debug)
+		fprintf(stderr, "fixed%s\n", sb.buf);
+	strbuf_release(&sb);
+	if (err) {
+		char errbuf[1024];
+		regerror(err, &p->regexp, errbuf, 1024);
+		regfree(&p->regexp);
+		compile_regexp_failed(p, errbuf);
+	}
+}
+
 static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
 {
 	int icase_non_ascii;
@@ -411,7 +430,11 @@ static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
 	if (!icase_non_ascii && is_fixed(p->pattern, p->patternlen))
 		p->fixed = 1;
 	else if (opt->fixed) {
-		p->fixed = 1;
+		p->fixed = !icase_non_ascii;
+		if (!p->fixed) {
+			compile_fixed_regexp(p, opt);
+			return;
+		}
 	} else
 		p->fixed = 0;
 
diff --git a/quote.c b/quote.c
index fe884d2..c67adb7 100644
--- a/quote.c
+++ b/quote.c
@@ -440,3 +440,40 @@ void tcl_quote_buf(struct strbuf *sb, const char *src)
 	}
 	strbuf_addch(sb, '"');
 }
+
+void basic_regex_quote_buf(struct strbuf *sb, const char *src)
+{
+	char c;
+
+	if (*src == '^') {
+		/* only beginning '^' is special and needs quoting */
+		strbuf_addch(sb, '\\');
+		strbuf_addch(sb, *src++);
+	}
+	if (*src == '*')
+		/* beginning '*' is not special, no quoting */
+		strbuf_addch(sb, *src++);
+
+	while ((c = *src++)) {
+		switch (c) {
+		case '[':
+		case '.':
+		case '\\':
+		case '*':
+			strbuf_addch(sb, '\\');
+			strbuf_addch(sb, c);
+			break;
+
+		case '$':
+			/* only the end '$' is special and needs quoting */
+			if (*src == '\0')
+				strbuf_addch(sb, '\\');
+			strbuf_addch(sb, c);
+			break;
+
+		default:
+			strbuf_addch(sb, c);
+			break;
+		}
+	}
+}
diff --git a/quote.h b/quote.h
index 99e04d3..362d315 100644
--- a/quote.h
+++ b/quote.h
@@ -67,5 +67,6 @@ extern char *quote_path_relative(const char *in, const char *prefix,
 extern void perl_quote_buf(struct strbuf *sb, const char *src);
 extern void python_quote_buf(struct strbuf *sb, const char *src);
 extern void tcl_quote_buf(struct strbuf *sb, const char *src);
+extern void basic_regex_quote_buf(struct strbuf *sb, const char *src);
 
 #endif
diff --git a/t/t7812-grep-icase-non-ascii.sh b/t/t7812-grep-icase-non-ascii.sh
index 6eff490..aba6b15 100755
--- a/t/t7812-grep-icase-non-ascii.sh
+++ b/t/t7812-grep-icase-non-ascii.sh
@@ -20,4 +20,30 @@ test_expect_success REGEX_LOCALE 'grep literal string, no -F' '
 	git grep -i "TILRAUN: HALLÓ HEIMUR!"
 '
 
+test_expect_success REGEX_LOCALE 'grep literal string, with -F' '
+	git grep --debug -i -F "TILRAUN: Halló Heimur!"  2>&1 >/dev/null |
+		 grep fixed >debug1 &&
+	echo "fixedTILRAUN: Halló Heimur!" >expect1 &&
+	test_cmp expect1 debug1 &&
+
+	git grep --debug -i -F "TILRAUN: HALLÓ HEIMUR!"  2>&1 >/dev/null |
+		 grep fixed >debug2 &&
+	echo "fixedTILRAUN: HALLÓ HEIMUR!" >expect2 &&
+	test_cmp expect2 debug2
+'
+
+test_expect_success REGEX_LOCALE 'grep string with regex, with -F' '
+	printf "^*TILR^AUN:.* \\Halló \$He[]imur!\$" >file &&
+
+	git grep --debug -i -F "^*TILR^AUN:.* \\Halló \$He[]imur!\$" 2>&1 >/dev/null |
+		 grep fixed >debug1 &&
+	echo "fixed\\^*TILR^AUN:\\.\\* \\\\Halló \$He\\[]imur!\\\$" >expect1 &&
+	test_cmp expect1 debug1 &&
+
+	git grep --debug -i -F "^*TILR^AUN:.* \\HALLÓ \$HE[]IMUR!\$"  2>&1 >/dev/null |
+		 grep fixed >debug2 &&
+	echo "fixed\\^*TILR^AUN:\\.\\* \\\\HALLÓ \$HE\\[]IMUR!\\\$" >expect2 &&
+	test_cmp expect2 debug2
+'
+
 test_done
-- 
2.7.0.288.g1d8ad15
Previous: Eric SunshineNext: Eric Sunshine
Message 10 of 56 in “Fix icase grep on non-ascii”
  1. 00/10 Fix icase grep on non-asciiNguyễn Thái Ngọc Duy, Jan 28, 2016
  2. 01/10 grep: allow -F -i combinationNguyễn Thái Ngọc Duy, Jan 28, 2016
  3. 02/10 grep: break down an "if" stmt in preparation for next changesNguyễn Thái Ngọc Duy, Jan 28, 2016
  4. 03/10 test-regex: expose full regcomp() to the command lineNguyễn Thái Ngọc Duy, Jan 28, 2016
  5. Eric SunshineJan 29, 2016
  6. Ramsay JonesJan 29, 2016
  7. 04/10 grep/icase: avoid kwsset on literal non-ascii stringsNguyễn Thái Ngọc Duy, Jan 28, 2016
  8. Eric SunshineJan 29, 2016
  9. Eric SunshineJan 29, 2016
  10. 05/10 grep/icase: avoid kwsset when -F is specifiedNguyễn Thái Ngọc Duy, Jan 28, 2016
  11. Eric SunshineJan 29, 2016
  12. 06/10 grep/pcre: prepare locale-dependent tables for icase matchingNguyễn Thái Ngọc Duy, Jan 28, 2016
  13. 07/10 gettext: add is_utf8_locale()Nguyễn Thái Ngọc Duy, Jan 28, 2016
  14. 08/10 grep/pcre: support utf-8Nguyễn Thái Ngọc Duy, Jan 28, 2016
  15. 09/10 diffcore-pickaxe: "share" regex error handling codeNguyễn Thái Ngọc Duy, Jan 28, 2016
  16. 10/10 diffcore-pickaxe: support case insensitive match on non-asciiNguyễn Thái Ngọc Duy, Jan 28, 2016
  17. Eric SunshineJan 29, 2016
  18. Junio C HamanoJan 28, 2016
  19. 00/11 Fix icase grep on non-asciiNguyễn Thái Ngọc Duy, Feb 6, 2016
  20. 01/11 grep: allow -F -i combinationNguyễn Thái Ngọc Duy, Feb 6, 2016
  21. Junio C HamanoJun 17, 2016
  22. Duy NguyenJun 18, 2016
  23. 02/11 grep: break down an "if" stmt in preparation for next changesNguyễn Thái Ngọc Duy, Feb 6, 2016
  24. Junio C HamanoFeb 9, 2016
  25. 03/11 test-regex: isolate the bug test codeNguyễn Thái Ngọc Duy, Feb 6, 2016
  26. 04/11 test-regex: expose full regcomp() to the command lineNguyễn Thái Ngọc Duy, Feb 6, 2016
  27. Eric SunshineFeb 7, 2016
  28. Junio C HamanoFeb 9, 2016
  29. 05/11 grep/icase: avoid kwsset on literal non-ascii stringsNguyễn Thái Ngọc Duy, Feb 6, 2016
  30. 06/11 grep/icase: avoid kwsset when -F is specifiedNguyễn Thái Ngọc Duy, Feb 6, 2016
  31. 07/11 grep/pcre: prepare locale-dependent tables for icase matchingNguyễn Thái Ngọc Duy, Feb 6, 2016
  32. 08/11 gettext: add is_utf8_locale()Nguyễn Thái Ngọc Duy, Feb 6, 2016
  33. 09/11 grep/pcre: support utf-8Nguyễn Thái Ngọc Duy, Feb 6, 2016
  34. 10/11 diffcore-pickaxe: "share" regex error handling codeNguyễn Thái Ngọc Duy, Feb 6, 2016
  35. 11/11 diffcore-pickaxe: support case insensitive match on non-asciiNguyễn Thái Ngọc Duy, Feb 6, 2016
  36. Eric SunshineFeb 7, 2016
  37. 00/12 nd/icase updatesNguyễn Thái Ngọc Duy, Feb 14, 2016
  38. 01/12 grep: allow -F -i combinationNguyễn Thái Ngọc Duy, Feb 14, 2016
  39. 02/12 grep: break down an "if" stmt in preparation for next changesNguyễn Thái Ngọc Duy, Feb 14, 2016
  40. 03/12 test-regex: isolate the bug test codeNguyễn Thái Ngọc Duy, Feb 14, 2016
  41. 04/12 test-regex: expose full regcomp() to the command lineNguyễn Thái Ngọc Duy, Feb 14, 2016
  42. 05/12 grep/icase: avoid kwsset on literal non-ascii stringsNguyễn Thái Ngọc Duy, Feb 14, 2016
  43. 06/12 grep/icase: avoid kwsset when -F is specifiedNguyễn Thái Ngọc Duy, Feb 14, 2016
  44. 07/12 grep/pcre: prepare locale-dependent tables for icase matchingNguyễn Thái Ngọc Duy, Feb 14, 2016
  45. 08/12 gettext: add is_utf8_locale()Nguyễn Thái Ngọc Duy, Feb 14, 2016
  46. 09/12 grep/pcre: support utf-8Nguyễn Thái Ngọc Duy, Feb 14, 2016
  47. 10/12 diffcore-pickaxe: "share" regex error handling codeNguyễn Thái Ngọc Duy, Feb 14, 2016
  48. 11/12 diffcore-pickaxe: support case insensitive match on non-asciiNguyễn Thái Ngọc Duy, Feb 14, 2016
  49. 12/12 grep.c: reuse "icase" variableNguyễn Thái Ngọc Duy, Feb 14, 2016
  50. Junio C HamanoJun 17, 2016
  51. Duy NguyenJun 18, 2016
  52. Duy NguyenJun 22, 2016
  53. Junio C HamanoJun 22, 2016
  54. Duy NguyenJun 22, 2016
  55. Junio C HamanoJun 22, 2016
  56. Junio C HamanoJun 22, 2016

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