Merge branch 'rs/maint-grep-F' into maint

"git grep -e '$pattern'", unlike the case where the patterns are read from
a file, did not treat individual lines in the given pattern argument as
separate regular expressions as it should.

By René Scharfe
* rs/maint-grep-F:
  grep: stop leaking line strings with -f
  grep: support newline separated pattern list
  grep: factor out do_append_grep_pat()
  grep: factor out create_grep_pat()

Documentation/git-grep.txt

@@ -31,7 +31,9 @@ SYNOPSIS
 DESCRIPTION
 -----------
 Look for specified patterns in the tracked files in the work tree, blobs
-registered in the index file, or blobs in given tree objects.
+registered in the index file, or blobs in given tree objects.  Patterns
+are lists of one or more search expressions separated by newline
+characters.  An empty string as search expression matches all lines.
 
 
 CONFIGURATION

builtin/grep.c

@@ -600,15 +600,12 @@ static int file_callback(const struct option *opt, const char *arg, int unset)
 	if (!patterns)
 		die_errno(_("cannot open '%s'"), arg);
 	while (strbuf_getline(&sb, patterns, '\n') == 0) {
-		char *s;
-		size_t len;
-
 		/* ignore empty line like grep does */
 		if (sb.len == 0)
 			continue;
 
-		s = strbuf_detach(&sb, &len);
-		append_grep_pat(grep_opt, s, len, arg, ++lno, GREP_PATTERN);
+		append_grep_pat(grep_opt, sb.buf, sb.len, arg, ++lno,
+				GREP_PATTERN);
 	}
 	if (!from_stdin)
 		fclose(patterns);

grep.c

@@ -3,18 +3,64 @@
 #include "userdiff.h"
 #include "xdiff-interface.h"
 
-void append_header_grep_pattern(struct grep_opt *opt, enum grep_header_field field, const char *pat)
+static struct grep_pat *create_grep_pat(const char *pat, size_t patlen,
+					const char *origin, int no,
+					enum grep_pat_token t,
+					enum grep_header_field field)
 {
 	struct grep_pat *p = xcalloc(1, sizeof(*p));
-	p->pattern = pat;
-	p->patternlen = strlen(pat);
-	p->origin = "header";
-	p->no = 0;
-	p->token = GREP_PATTERN_HEAD;
+	p->pattern = xmemdupz(pat, patlen);
+	p->patternlen = patlen;
+	p->origin = origin;
+	p->no = no;
+	p->token = t;
 	p->field = field;
-	*opt->header_tail = p;
-	opt->header_tail = &p->next;
+	return p;
+}
+
+static void do_append_grep_pat(struct grep_pat ***tail, struct grep_pat *p)
+{
+	**tail = p;
+	*tail = &p->next;
 	p->next = NULL;
+
+	switch (p->token) {
+	case GREP_PATTERN: /* atom */
+	case GREP_PATTERN_HEAD:
+	case GREP_PATTERN_BODY:
+		for (;;) {
+			struct grep_pat *new_pat;
+			size_t len = 0;
+			char *cp = p->pattern + p->patternlen, *nl = NULL;
+			while (++len <= p->patternlen) {
+				if (*(--cp) == '\n') {
+					nl = cp;
+					break;
+				}
+			}
+			if (!nl)
+				break;
+			new_pat = create_grep_pat(nl + 1, len - 1, p->origin,
+						  p->no, p->token, p->field);
+			new_pat->next = p->next;
+			if (!p->next)
+				*tail = &new_pat->next;
+			p->next = new_pat;
+			*nl = '\0';
+			p->patternlen -= len;
+		}
+		break;
+	default:
+		break;
+	}
+}
+
+void append_header_grep_pattern(struct grep_opt *opt,
+				enum grep_header_field field, const char *pat)
+{
+	struct grep_pat *p = create_grep_pat(pat, strlen(pat), "header", 0,
+					     GREP_PATTERN_HEAD, field);
+	do_append_grep_pat(&opt->header_tail, p);
 }
 
 void append_grep_pattern(struct grep_opt *opt, const char *pat,
@@ -26,15 +72,8 @@ void append_grep_pattern(struct grep_opt *opt, const char *pat,
 void append_grep_pat(struct grep_opt *opt, const char *pat, size_t patlen,
 		     const char *origin, int no, enum grep_pat_token t)
 {
-	struct grep_pat *p = xcalloc(1, sizeof(*p));
-	p->pattern = pat;
-	p->patternlen = patlen;
-	p->origin = origin;
-	p->no = no;
-	p->token = t;
-	*opt->pattern_tail = p;
-	opt->pattern_tail = &p->next;
-	p->next = NULL;
+	struct grep_pat *p = create_grep_pat(pat, patlen, origin, no, t, 0);
+	do_append_grep_pat(&opt->pattern_tail, p);
 }
 
 struct grep_opt *grep_opt_dup(const struct grep_opt *opt)
@@ -430,6 +469,7 @@ void free_grep_patterns(struct grep_opt *opt)
 				free_pcre_regexp(p);
 			else
 				regfree(&p->regexp);
+			free(p->pattern);
 			break;
 		default:
 			break;

grep.h

@@ -38,7 +38,7 @@ struct grep_pat {
 	const char *origin;
 	int no;
 	enum grep_pat_token token;
-	const char *pattern;
+	char *pattern;
 	size_t patternlen;
 	enum grep_header_field field;
 	regex_t regexp;

t/t7810-grep.sh

@@ -351,6 +351,11 @@ test_expect_success 'grep -f, multiple patterns' '
 	test_cmp expected actual
 '
 
+test_expect_success 'grep, multiple patterns' '
+	git grep "$(cat patterns)" >actual &&
+	test_cmp expected actual
+'
+
 cat >expected <<EOF
 file:foo mmap bar
 file:foo_mmap bar