Revert "Merge branch 'nd/exclusion-regression-fix'"

This reverts commit 5e57f9c3dfe7dd44a1b56bb5b3327d7a1356ec7c, reversing
changes made to e79112d21024beb997951381db21a70b087d459d.

We will be postponing nd/exclusion-regression-fix topic to later
cycle.

7 files changed, 12 insertions, 378 deletions

diff --git a/Documentation/git-check-ignore.txt b/Documentation/git-check-ignore.txt
index f60ee051f8..e94367a5ed 100644
--- a/Documentation/git-check-ignore.txt
+++ b/Documentation/git-check-ignore.txt
@@ -114,7 +114,6 @@ SEE ALSO
 linkgit:gitignore[5]
 linkgit:gitconfig[5]
 linkgit:git-ls-files[1]
-GIT_TRACE_EXCLUDE in linkgit:git[1]
 
 GIT
 ---
diff --git a/Documentation/git.txt b/Documentation/git.txt
index 5f3647ea31..a9120a8779 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt
@@ -1069,11 +1069,6 @@ of clones and fetches.
 	cloning of shallow repositories.
 	See 'GIT_TRACE' for available trace output options.
 
-'GIT_TRACE_EXCLUDE'::
-	Enables trace messages that can help debugging .gitignore
-	processing. See 'GIT_TRACE' for available trace output
-	options.
-
 'GIT_LITERAL_PATHSPECS'::
 	Setting this variable to `1` will cause Git to treat all
 	pathspecs literally, rather than as glob patterns. For example,
diff --git a/Documentation/gitignore.txt b/Documentation/gitignore.txt
index 3ded6fdc99..473623d631 100644
--- a/Documentation/gitignore.txt
+++ b/Documentation/gitignore.txt
@@ -82,12 +82,12 @@ PATTERN FORMAT
 
  - An optional prefix "`!`" which negates the pattern; any
    matching file excluded by a previous pattern will become
-   included again.
+   included again. It is not possible to re-include a file if a parent
+   directory of that file is excluded. Git doesn't list excluded
+   directories for performance reasons, so any patterns on contained
+   files have no effect, no matter where they are defined.
    Put a backslash ("`\`") in front of the first "`!`" for patterns
    that begin with a literal "`!`", for example, "`\!important!.txt`".
-   It is possible to re-include a file if a parent directory of that
-   file is excluded if certain conditions are met. See section NOTES
-   for detail.
 
  - If the pattern ends with a slash, it is removed for the
    purpose of the following description, but it would only find
@@ -141,15 +141,6 @@ not tracked by Git remain untracked.
 To stop tracking a file that is currently tracked, use
 'git rm --cached'.
 
-To re-include files or directories when their parent directory is
-excluded, the following conditions must be met:
-
- - The rules to exclude a directory and re-include a subset back must
-   be in the same .gitignore file.
-
- - The directory part in the re-include rules must be literal (i.e. no
-   wildcards)
-
 EXAMPLES
 --------
 
diff --git a/dir.c b/dir.c
index 69e0be6aa2..a4a9d9fae1 100644
--- a/dir.c
+++ b/dir.c
@@ -53,8 +53,6 @@ static enum path_treatment read_directory_recursive(struct dir_struct *dir,
 	int check_only, const struct path_simplify *simplify);
 static int get_dtype(struct dirent *de, const char *path, int len);
 
-static struct trace_key trace_exclude = TRACE_KEY_INIT(EXCLUDE);
-
 /* helper string functions with support for the ignore_case flag */
 int strcmp_icase(const char *a, const char *b)
 {
@@ -516,7 +514,6 @@ void add_exclude(const char *string, const char *base,
 	x->baselen = baselen;
 	x->flags = flags;
 	x->srcpos = srcpos;
-	string_list_init(&x->sticky_paths, 1);
 	ALLOC_GROW(el->excludes, el->nr + 1, el->alloc);
 	el->excludes[el->nr++] = x;
 	x->el = el;
@@ -557,10 +554,8 @@ void clear_exclude_list(struct exclude_list *el)
 {
 	int i;
 
-	for (i = 0; i < el->nr; i++) {
-		string_list_clear(&el->excludes[i]->sticky_paths, 0);
+	for (i = 0; i < el->nr; i++)
 		free(el->excludes[i]);
-	}
 	free(el->excludes);
 	free(el->filebuf);
 
@@ -875,7 +870,7 @@ int match_pathname(const char *pathname, int pathlen,
 		 * then our prefix match is all we need; we
 		 * do not need to call fnmatch at all.
 		 */
-		if (!patternlen && (!namelen || *name == '/'))
+		if (!patternlen && !namelen)
 			return 1;
 	}
 
@@ -884,113 +879,6 @@ int match_pathname(const char *pathname, int pathlen,
 				 WM_PATHNAME) == 0;
 }
 
-static void add_sticky(struct exclude *exc, const char *pathname, int pathlen)
-{
-	struct strbuf sb = STRBUF_INIT;
-	int i;
-
-	for (i = exc->sticky_paths.nr - 1; i >= 0; i--) {
-		const char *sticky = exc->sticky_paths.items[i].string;
-		int len = strlen(sticky);
-
-		if (pathlen < len && sticky[pathlen] == '/' &&
-		    !strncmp(pathname, sticky, pathlen))
-			return;
-	}
-
-	strbuf_add(&sb, pathname, pathlen);
-	string_list_append_nodup(&exc->sticky_paths, strbuf_detach(&sb, NULL));
-}
-
-static int match_sticky(struct exclude *exc, const char *pathname, int pathlen, int dtype)
-{
-	int i;
-
-	for (i = exc->sticky_paths.nr - 1; i >= 0; i--) {
-		const char *sticky = exc->sticky_paths.items[i].string;
-		int len = strlen(sticky);
-
-		if (pathlen == len && dtype == DT_DIR &&
-		    !strncmp(pathname, sticky, len))
-			return 1;
-
-		if (pathlen > len && pathname[len] == '/' &&
-		    !strncmp(pathname, sticky, len))
-			return 1;
-	}
-
-	return 0;
-}
-
-static inline int different_decisions(const struct exclude *a,
-				      const struct exclude *b)
-{
-	return (a->flags & EXC_FLAG_NEGATIVE) != (b->flags & EXC_FLAG_NEGATIVE);
-}
-
-/*
- * Return non-zero if pathname is a directory and an ancestor of the
- * literal path in a pattern.
- */
-static int match_directory_part(const char *pathname, int pathlen,
-				int *dtype, struct exclude *x)
-{
-	const char	*base	    = x->base;
-	int		 baselen    = x->baselen ? x->baselen - 1 : 0;
-	const char	*pattern    = x->pattern;
-	int		 prefix	    = x->nowildcardlen;
-	int		 patternlen = x->patternlen;
-
-	if (*dtype == DT_UNKNOWN)
-		*dtype = get_dtype(NULL, pathname, pathlen);
-	if (*dtype != DT_DIR)
-		return 0;
-
-	if (*pattern == '/') {
-		pattern++;
-		patternlen--;
-		prefix--;
-	}
-
-	if (baselen) {
-		if (((pathlen < baselen && base[pathlen] == '/') ||
-		     pathlen == baselen) &&
-		    !strncmp_icase(pathname, base, pathlen))
-			return 1;
-		pathname += baselen + 1;
-		pathlen  -= baselen + 1;
-	}
-
-
-	if (prefix &&
-	    (((pathlen < prefix && pattern[pathlen] == '/') ||
-	      pathlen == prefix) &&
-	     !strncmp_icase(pathname, pattern, pathlen)))
-		return 1;
-
-	return 0;
-}
-
-static struct exclude *should_descend(const char *pathname, int pathlen,
-				      int *dtype, struct exclude_list *el,
-				      struct exclude *exc)
-{
-	int i;
-
-	for (i = el->nr - 1; 0 <= i; i--) {
-		struct exclude *x = el->excludes[i];
-
-		if (x == exc)
-			break;
-
-		if (!(x->flags & EXC_FLAG_NODIR) &&
-		    different_decisions(x, exc) &&
-		    match_directory_part(pathname, pathlen, dtype, x))
-			return x;
-	}
-	return NULL;
-}
-
 /*
  * Scan the given exclude list in reverse to see whether pathname
  * should be ignored.  The first match (i.e. the last on the list), if
@@ -1004,32 +892,16 @@ static struct exclude *last_exclude_matching_from_list(const char *pathname,
 						       struct exclude_list *el)
 {
 	struct exclude *exc = NULL; /* undecided */
-	int i, maybe_descend = 0;
+	int i;
 
 	if (!el->nr)
 		return NULL;	/* undefined */
 
-	trace_printf_key(&trace_exclude, "exclude: from %s\n", el->src);
-
 	for (i = el->nr - 1; 0 <= i; i--) {
 		struct exclude *x = el->excludes[i];
 		const char *exclude = x->pattern;
 		int prefix = x->nowildcardlen;
 
-		if (!maybe_descend && i < el->nr - 1 &&
-		    different_decisions(x, el->excludes[i+1]))
-			maybe_descend = 1;
-
-		if (x->sticky_paths.nr) {
-			if (*dtype == DT_UNKNOWN)
-				*dtype = get_dtype(NULL, pathname, pathlen);
-			if (match_sticky(x, pathname, pathlen, *dtype)) {
-				exc = x;
-				break;
-			}
-			continue;
-		}
-
 		if (x->flags & EXC_FLAG_MUSTBEDIR) {
 			if (*dtype == DT_UNKNOWN)
 				*dtype = get_dtype(NULL, pathname, pathlen);
@@ -1056,45 +928,6 @@ static struct exclude *last_exclude_matching_from_list(const char *pathname,
 			break;
 		}
 	}
-
-	if (!exc) {
-		trace_printf_key(&trace_exclude, "exclude: %.*s => n/a\n",
-				 pathlen, pathname);
-		return NULL;
-	}
-
-	/*
-	 * We have found a matching pattern "exc" that may exclude whole
-	 * directory. We also found that there may be a pattern that matches
-	 * something inside the directory and reincludes stuff.
-	 *
-	 * Go through the patterns again, find that pattern and double check.
-	 * If it's true, return "undecided" and keep descending in. "exc" is
-	 * marked sticky so that it continues to match inside the directory.
-	 */
-	if (!(exc->flags & EXC_FLAG_NEGATIVE) && maybe_descend) {
-		struct exclude *x;
-
-		if (*dtype == DT_UNKNOWN)
-			*dtype = get_dtype(NULL, pathname, pathlen);
-
-		if (*dtype == DT_DIR &&
-		    (x = should_descend(pathname, pathlen, dtype, el, exc))) {
-			add_sticky(exc, pathname, pathlen);
-			trace_printf_key(&trace_exclude,
-					 "exclude: %.*s vs %s at line %d => %s,"
-					 " forced open by %s at line %d => n/a\n",
-					 pathlen, pathname, exc->pattern, exc->srcpos,
-					 exc->flags & EXC_FLAG_NEGATIVE ? "no" : "yes",
-					 x->pattern, x->srcpos);
-			return NULL;
-		}
-	}
-
-	trace_printf_key(&trace_exclude, "exclude: %.*s vs %s at line %d => %s%s\n",
-			 pathlen, pathname, exc->pattern, exc->srcpos,
-			 exc->flags & EXC_FLAG_NEGATIVE ? "no" : "yes",
-			 exc->sticky_paths.nr ? " (stuck)" : "");
 	return exc;
 }
 
@@ -1840,13 +1673,9 @@ static enum path_treatment read_directory_recursive(struct dir_struct *dir,
 	struct cached_dir cdir;
 	enum path_treatment state, subdir_state, dir_state = path_none;
 	struct strbuf path = STRBUF_INIT;
-	static int level = 0;
 
 	strbuf_add(&path, base, baselen);
 
-	trace_printf_key(&trace_exclude, "exclude: [%d] enter '%.*s'\n",
-			 level++, baselen, base);
-
 	if (open_cached_dir(&cdir, dir, untracked, &path, check_only))
 		goto out;
 
@@ -1910,8 +1739,6 @@ static enum path_treatment read_directory_recursive(struct dir_struct *dir,
 	}
 	close_cached_dir(&cdir);
  out:
-	trace_printf_key(&trace_exclude, "exclude: [%d] leave '%.*s'\n",
-			 --level, baselen, base);
 	strbuf_release(&path);
 
 	return dir_state;
@@ -2148,25 +1975,6 @@ static struct untracked_cache_dir *validate_untracked_cache(struct dir_struct *d
 	return root;
 }
 
-static void clear_sticky(struct dir_struct *dir)
-{
-	struct exclude_list_group *g;
-	struct exclude_list *el;
-	struct exclude *x;
-	int i, j, k;
-
-	for (i = EXC_CMDL; i <= EXC_FILE; i++) {
-		g = &dir->exclude_list_group[i];
-		for (j = g->nr - 1; j >= 0; j--) {
-			el = &g->el[j];
-			for (k = el->nr - 1; 0 <= k; k--) {
-				x = el->excludes[k];
-				string_list_clear(&x->sticky_paths, 0);
-			}
-		}
-	}
-}
-
 int read_directory(struct dir_struct *dir, const char *path, int len, const struct pathspec *pathspec)
 {
 	struct path_simplify *simplify;
@@ -2188,12 +1996,6 @@ int read_directory(struct dir_struct *dir, const char *path, int len, const stru
 		return dir->nr;
 
 	/*
-	 * Stay on the safe side. if read_directory() has run once on
-	 * "dir", some sticky flag may have been left. Clear them all.
-	 */
-	clear_sticky(dir);
-
-	/*
 	 * exclude patterns are treated like positive ones in
 	 * create_simplify. Usually exclude patterns should be a
 	 * subset of positive ones, which has no impacts on
diff --git a/dir.h b/dir.h
index 3ec3fb0dca..cd46f30017 100644
--- a/dir.h
+++ b/dir.h
@@ -4,7 +4,6 @@
 /* See Documentation/technical/api-directory-listing.txt */
 
 #include "strbuf.h"
-#include "string-list.h"
 
 struct dir_entry {
 	unsigned int len;
@@ -35,8 +34,6 @@ struct exclude {
 	 * and from -1 decrementing for patterns from CLI args.
 	 */
 	int srcpos;
-
-	struct string_list sticky_paths;
 };
 
 /*
diff --git a/t/t3001-ls-files-others-exclude.sh b/t/t3001-ls-files-others-exclude.sh
index d043078da5..3fc484e8c3 100755
--- a/t/t3001-ls-files-others-exclude.sh
+++ b/t/t3001-ls-files-others-exclude.sh
@@ -175,10 +175,13 @@ test_expect_success 'negated exclude matches can override previous ones' '
 	grep "^a.1" output
 '
 
-test_expect_success 'excluded directory does not override content patterns' '
+test_expect_success 'excluded directory overrides content patterns' '
 
 	git ls-files --others --exclude="one" --exclude="!one/a.1" >output &&
-	grep "^one/a.1" output
+	if grep "^one/a.1" output
+	then
+		false
+	fi
 '
 
 test_expect_success 'negated directory doesn'\''t affect content patterns' '
diff --git a/t/t3007-ls-files-other-negative.sh b/t/t3007-ls-files-other-negative.sh
deleted file mode 100755
index 0797b86ad0..0000000000
--- a/t/t3007-ls-files-other-negative.sh
+++ /dev/null
@@ -1,153 +0,0 @@
-#!/bin/sh
-
-test_description='test re-include patterns'
-
-. ./test-lib.sh
-
-test_expect_success 'setup' '
-	mkdir -p fooo foo/bar tmp &&
-	touch abc foo/def foo/bar/ghi foo/bar/bar
-'
-
-test_expect_success 'no match, do not enter subdir and waste cycles' '
-	cat >.gitignore <<-\EOF &&
-	/tmp
-	/foo
-	!fooo/bar/bar
-	EOF
-	GIT_TRACE_EXCLUDE="$(pwd)/tmp/trace" git ls-files -o --exclude-standard >tmp/actual &&
-	! grep "enter .foo/.\$" tmp/trace &&
-	cat >tmp/expected <<-\EOF &&
-	.gitignore
-	abc
-	EOF
-	test_cmp tmp/expected tmp/actual
-'
-
-test_expect_success 'match, excluded by literal pathname pattern' '
-	cat >.gitignore <<-\EOF &&
-	/tmp
-	/fooo
-	/foo
-	!foo/bar/bar
-	EOF
-	cat >fooo/.gitignore <<-\EOF &&
-	!/*
-	EOF	git ls-files -o --exclude-standard >tmp/actual &&
-	cat >tmp/expected <<-\EOF &&
-	.gitignore
-	abc
-	foo/bar/bar
-	EOF
-	test_cmp tmp/expected tmp/actual
-'
-
-test_expect_success 'match, excluded by wildcard pathname pattern' '
-	cat >.gitignore <<-\EOF &&
-	/tmp
-	/fooo
-	/fo?
-	!foo/bar/bar
-	EOF
-	git ls-files -o --exclude-standard >tmp/actual &&
-	cat >tmp/expected <<-\EOF &&
-	.gitignore
-	abc
-	foo/bar/bar
-	EOF
-	test_cmp tmp/expected tmp/actual
-'
-
-test_expect_success 'match, excluded by literal basename pattern' '
-	cat >.gitignore <<-\EOF &&
-	/tmp
-	/fooo
-	foo
-	!foo/bar/bar
-	EOF
-	git ls-files -o --exclude-standard >tmp/actual &&
-	cat >tmp/expected <<-\EOF &&
-	.gitignore
-	abc
-	foo/bar/bar
-	EOF
-	test_cmp tmp/expected tmp/actual
-'
-
-test_expect_success 'match, excluded by wildcard basename pattern' '
-	cat >.gitignore <<-\EOF &&
-	/tmp
-	/fooo
-	fo?
-	!foo/bar/bar
-	EOF
-	git ls-files -o --exclude-standard >tmp/actual &&
-	cat >tmp/expected <<-\EOF &&
-	.gitignore
-	abc
-	foo/bar/bar
-	EOF
-	test_cmp tmp/expected tmp/actual
-'
-
-test_expect_success 'match, excluded by literal mustbedir, basename pattern' '
-	cat >.gitignore <<-\EOF &&
-	/tmp
-	/fooo
-	foo/
-	!foo/bar/bar
-	EOF
-	git ls-files -o --exclude-standard >tmp/actual &&
-	cat >tmp/expected <<-\EOF &&
-	.gitignore
-	abc
-	foo/bar/bar
-	EOF
-	test_cmp tmp/expected tmp/actual
-'
-
-test_expect_success 'match, excluded by literal mustbedir, pathname pattern' '
-	cat >.gitignore <<-\EOF &&
-	/tmp
-	/fooo
-	/foo/
-	!foo/bar/bar
-	EOF
-	git ls-files -o --exclude-standard >tmp/actual &&
-	cat >tmp/expected <<-\EOF &&
-	.gitignore
-	abc
-	foo/bar/bar
-	EOF
-	test_cmp tmp/expected tmp/actual
-'
-
-test_expect_success 'prepare for nested negatives' '
-	cat >.git/info/exclude <<-\EOF &&
-	/.gitignore
-	/tmp
-	/foo
-	/abc
-	EOF
-	git ls-files -o --exclude-standard >tmp/actual &&
-	test_must_be_empty tmp/actual &&
-	mkdir -p 1/2/3/4 &&
-	touch 1/f 1/2/f 1/2/3/f 1/2/3/4/f
-'
-
-test_expect_success 'match, literal pathname, nested negatives' '
-	cat >.gitignore <<-\EOF &&
-	/1
-	!1/2
-	1/2/3
-	!1/2/3/4
-	EOF
-	git ls-files -o --exclude-standard >tmp/actual &&
-	cat >tmp/expected <<-\EOF &&
-	1/2/3/4/f
-	1/2/f
-	EOF
-	test_cmp tmp/expected tmp/actual
-'
-
-test_done