Merge branch 'as/check-ignore'

Enhance "check-ignore" (1.8.2 update) to work more like "check-attr"
over bidi-pipes.

* as/check-ignore:
  t0008: use named pipe (FIFO) to test check-ignore streaming
  Documentation: add caveats about I/O buffering for check-{attr,ignore}
  check-ignore: allow incremental streaming of queries via --stdin
  check-ignore: move setup into cmd_check_ignore()
  check-ignore: add -n / --non-matching option
  t0008: remove duplicated test fixture data

Author: gitster

Documentation/git-check-attr.txt

@@ -56,6 +56,11 @@ being queried and <info> can be either:
 'set';;		when the attribute is defined as true.
 <value>;;	when a value has been assigned to the attribute.
 
+Buffering happens as documented under the `GIT_FLUSH` option in
+linkgit:git[1].  The caller is responsible for avoiding deadlocks
+caused by overfilling an input buffer or reading from an empty output
+buffer.
+
 EXAMPLES
 --------
 

Documentation/git-check-ignore.txt

@@ -39,6 +39,12 @@ OPTIONS
 	below).  If `--stdin` is also given, input paths are separated
 	with a NUL character instead of a linefeed character.
 
+-n, --non-matching::
+	Show given paths which don't match any pattern.	 This only
+	makes sense when `--verbose` is enabled, otherwise it would
+	not be possible to distinguish between paths which match a
+	pattern and those which don't.
+
 OUTPUT
 ------
 
@@ -65,6 +71,20 @@ are also used instead of colons and hard tabs:
 
 <source> <NULL> <linenum> <NULL> <pattern> <NULL> <pathname> <NULL>
 
+If `-n` or `--non-matching` are specified, non-matching pathnames will
+also be output, in which case all fields in each output record except
+for <pathname> will be empty.  This can be useful when running
+non-interactively, so that files can be incrementally streamed to
+STDIN of a long-running check-ignore process, and for each of these
+files, STDOUT will indicate whether that file matched a pattern or
+not.  (Without this option, it would be impossible to tell whether the
+absence of output for a given file meant that it didn't match any
+pattern, or that the output hadn't been generated yet.)
+
+Buffering happens as documented under the `GIT_FLUSH` option in
+linkgit:git[1].  The caller is responsible for avoiding deadlocks
+caused by overfilling an input buffer or reading from an empty output
+buffer.
 
 EXIT STATUS
 -----------

Documentation/git.txt

@@ -811,8 +811,9 @@ for further details.
 'GIT_FLUSH'::
 	If this environment variable is set to "1", then commands such
 	as 'git blame' (in incremental mode), 'git rev-list', 'git log',
-	and 'git whatchanged' will force a flush of the output stream
-	after each commit-oriented record have been flushed.   If this
+	'git check-attr', 'git check-ignore', and 'git whatchanged' will
+	force a flush of the output stream after each record have been
+	flushed. If this
 	variable is set to "0", the output of these commands will be done
 	using completely buffered I/O.   If this environment variable is
 	not set, Git will choose buffered or record-oriented flushing

builtin/check-ignore.c

@@ -5,7 +5,7 @@
 #include "pathspec.h"
 #include "parse-options.h"
 
-static int quiet, verbose, stdin_paths;
+static int quiet, verbose, stdin_paths, show_non_matching;
 static const char * const check_ignore_usage[] = {
 "git check-ignore [options] pathname...",
 "git check-ignore [options] --stdin < <list-of-paths>",
@@ -22,52 +22,55 @@ static const struct option check_ignore_options[] = {
 		    N_("read file names from stdin")),
 	OPT_BOOLEAN('z', NULL, &null_term_line,
 		    N_("input paths are terminated by a null character")),
+	OPT_BOOLEAN('n', "non-matching", &show_non_matching,
+		    N_("show non-matching input paths")),
 	OPT_END()
 };
 
 static void output_exclude(const char *path, struct exclude *exclude)
 {
-	char *bang  = exclude->flags & EXC_FLAG_NEGATIVE  ? "!" : "";
-	char *slash = exclude->flags & EXC_FLAG_MUSTBEDIR ? "/" : "";
+	char *bang  = (exclude && exclude->flags & EXC_FLAG_NEGATIVE)  ? "!" : "";
+	char *slash = (exclude && exclude->flags & EXC_FLAG_MUSTBEDIR) ? "/" : "";
 	if (!null_term_line) {
 		if (!verbose) {
 			write_name_quoted(path, stdout, '\n');
 		} else {
-			quote_c_style(exclude->el->src, NULL, stdout, 0);
-			printf(":%d:%s%s%s\t",
-			       exclude->srcpos,
-			       bang, exclude->pattern, slash);
+			if (exclude) {
+				quote_c_style(exclude->el->src, NULL, stdout, 0);
+				printf(":%d:%s%s%s\t",
+				       exclude->srcpos,
+				       bang, exclude->pattern, slash);
+			}
+			else {
+				printf("::\t");
+			}
 			quote_c_style(path, NULL, stdout, 0);
 			fputc('\n', stdout);
 		}
 	} else {
 		if (!verbose) {
 			printf("%s%c", path, '\0');
 		} else {
-			printf("%s%c%d%c%s%s%s%c%s%c",
-			       exclude->el->src, '\0',
-			       exclude->srcpos, '\0',
-			       bang, exclude->pattern, slash, '\0',
-			       path, '\0');
+			if (exclude)
+				printf("%s%c%d%c%s%s%s%c%s%c",
+				       exclude->el->src, '\0',
+				       exclude->srcpos, '\0',
+				       bang, exclude->pattern, slash, '\0',
+				       path, '\0');
+			else
+				printf("%c%c%c%s%c", '\0', '\0', '\0', path, '\0');
 		}
 	}
 }
 
-static int check_ignore(const char *prefix, const char **pathspec)
+static int check_ignore(struct dir_struct *dir,
+			const char *prefix, const char **pathspec)
 {
-	struct dir_struct dir;
 	const char *path, *full_path;
 	char *seen;
 	int num_ignored = 0, dtype = DT_UNKNOWN, i;
 	struct exclude *exclude;
 
-	/* read_cache() is only necessary so we can watch out for submodules. */
-	if (read_cache() < 0)
-		die(_("index file corrupt"));
-
-	memset(&dir, 0, sizeof(dir));
-	setup_standard_excludes(&dir);
-
 	if (!pathspec || !*pathspec) {
 		if (!quiet)
 			fprintf(stderr, "no pathspec given.\n");
@@ -86,28 +89,26 @@ static int check_ignore(const char *prefix, const char **pathspec)
 					? strlen(prefix) : 0, path);
 		full_path = check_path_for_gitlink(full_path);
 		die_if_path_beyond_symlink(full_path, prefix);
+		exclude = NULL;
 		if (!seen[i]) {
-			exclude = last_exclude_matching(&dir, full_path, &dtype);
-			if (exclude) {
-				if (!quiet)
-					output_exclude(path, exclude);
-				num_ignored++;
-			}
+			exclude = last_exclude_matching(dir, full_path, &dtype);
 		}
+		if (!quiet && (exclude || show_non_matching))
+			output_exclude(path, exclude);
+		if (exclude)
+			num_ignored++;
 	}
 	free(seen);
-	clear_directory(&dir);
 
 	return num_ignored;
 }
 
-static int check_ignore_stdin_paths(const char *prefix)
+static int check_ignore_stdin_paths(struct dir_struct *dir, const char *prefix)
 {
 	struct strbuf buf, nbuf;
-	char **pathspec = NULL;
-	size_t nr = 0, alloc = 0;
+	char *pathspec[2] = { NULL, NULL };
 	int line_termination = null_term_line ? 0 : '\n';
-	int num_ignored;
+	int num_ignored = 0;
 
 	strbuf_init(&buf, 0);
 	strbuf_init(&nbuf, 0);
@@ -118,23 +119,19 @@ static int check_ignore_stdin_paths(const char *prefix)
 				die("line is badly quoted");
 			strbuf_swap(&buf, &nbuf);
 		}
-		ALLOC_GROW(pathspec, nr + 1, alloc);
-		pathspec[nr] = xcalloc(strlen(buf.buf) + 1, sizeof(*buf.buf));
-		strcpy(pathspec[nr++], buf.buf);
+		pathspec[0] = buf.buf;
+		num_ignored += check_ignore(dir, prefix, (const char **)pathspec);
+		maybe_flush_or_die(stdout, "check-ignore to stdout");
 	}
-	ALLOC_GROW(pathspec, nr + 1, alloc);
-	pathspec[nr] = NULL;
-	num_ignored = check_ignore(prefix, (const char **)pathspec);
-	maybe_flush_or_die(stdout, "attribute to stdout");
 	strbuf_release(&buf);
 	strbuf_release(&nbuf);
-	free(pathspec);
 	return num_ignored;
 }
 
 int cmd_check_ignore(int argc, const char **argv, const char *prefix)
 {
 	int num_ignored;
+	struct dir_struct dir;
 
 	git_config(git_default_config, NULL);
 
@@ -156,13 +153,24 @@ int cmd_check_ignore(int argc, const char **argv, const char *prefix)
 		if (verbose)
 			die(_("cannot have both --quiet and --verbose"));
 	}
+	if (show_non_matching && !verbose)
+		die(_("--non-matching is only valid with --verbose"));
+
+	/* read_cache() is only necessary so we can watch out for submodules. */
+	if (read_cache() < 0)
+		die(_("index file corrupt"));
+
+	memset(&dir, 0, sizeof(dir));
+	setup_standard_excludes(&dir);
 
 	if (stdin_paths) {
-		num_ignored = check_ignore_stdin_paths(prefix);
+		num_ignored = check_ignore_stdin_paths(&dir, prefix);
 	} else {
-		num_ignored = check_ignore(prefix, argv);
+		num_ignored = check_ignore(&dir, prefix, argv);
 		maybe_flush_or_die(stdout, "ignore to stdout");
 	}
 
+	clear_directory(&dir);
+
 	return !num_ignored;
 }