From e2f526768e1d91893dc2772962be8155205b9c50 Mon Sep 17 00:00:00 2001
From: Tavian Barnes <tavianator@tavianator.com>
Date: Tue, 3 Sep 2019 17:08:10 -0400
Subject: color: Fix directory coloring when resolving symlinks at the root

---
 color.c                 | 69 ++++++++++++++++++++++++++++++-------------------
 tests.sh                | 25 ++++++++++++++++++
 tests/test_color_ls.out |  6 +++++
 3 files changed, 73 insertions(+), 27 deletions(-)
 create mode 100644 tests/test_color_ls.out

diff --git a/color.c b/color.c
index 9c3c200..dde989d 100644
--- a/color.c
+++ b/color.c
@@ -716,49 +716,61 @@ static int print_colored(const struct colors *colors, const char *esc, const cha
 
 /** Find the offset of the first broken path component. */
 static ssize_t first_broken_offset(const char *path, const struct BFTW *ftwbuf, enum bfs_stat_flag flags, size_t max) {
+	ssize_t ret = max;
+
 	if (bftw_typeflag(ftwbuf, flags) != BFTW_ERROR) {
-		return max;
+		goto out;
 	}
 
+	char *at_path;
 	int at_fd;
-	if (path != ftwbuf->path) {
-		// We're in print_link_target(), so resolve relative to the parent directory
-		at_fd = ftwbuf->at_fd;
-	} else if (ftwbuf->depth == 0) {
-		at_fd = AT_FDCWD;
+	if (path == ftwbuf->path) {
+		if (ftwbuf->depth == 0) {
+			at_fd = AT_FDCWD;
+			at_path = dstrndup(path, max);
+		} else {
+			// The parent must have existed to get here
+			goto out;
+		}
 	} else {
-		// The parent must have existed to get here
-		return max;
+		// We're in print_link_target(), so resolve relative to the link's parent directory
+		at_fd = AT_FDCWD;
+		if (at_fd == AT_FDCWD && path[0] != '/') {
+			at_path = dstrndup(ftwbuf->path, ftwbuf->nameoff);
+			if (at_path && dstrncat(&at_path, path, max) != 0) {
+				ret = -1;
+				goto out_path;
+			}
+		} else {
+			at_path = dstrndup(path, max);
+		}
 	}
 
-	char *copy = dstralloc(max);
-	if (!copy) {
-		return 0;
+	if (!at_path) {
+		ret = -1;
+		goto out;
 	}
 
-	size_t i = 0;
-	while (i < max) {
-		size_t j = i;
-		while (path[j] != '/') {
-			++j;
-		}
-		while (path[j] == '/') {
-			++j;
-		}
-
-		if (dstrncat(&copy, path + i, j - i) != 0) {
+	while (ret > 0) {
+		if (xfaccessat(at_fd, at_path, F_OK) == 0) {
 			break;
 		}
 
-		if (xfaccessat(at_fd, copy, F_OK) != 0) {
-			break;
+		size_t len = dstrlen(at_path);
+		while (ret && at_path[len - 1] == '/') {
+			--len, --ret;
+		}
+		while (ret && at_path[len - 1] != '/') {
+			--len, --ret;
 		}
 
-		i = j;
+		dstresize(&at_path, len);
 	}
 
-	dstrfree(copy);
-	return i;
+out_path:
+	dstrfree(at_path);
+out:
+	return ret;
 }
 
 /** Print the directories leading up to a file. */
@@ -767,6 +779,9 @@ static int print_dirs_colored(CFILE *cfile, const char *path, const struct BFTW
 	FILE *file = cfile->file;
 
 	size_t broken = first_broken_offset(path, ftwbuf, flags, nameoff);
+	if (broken < 0) {
+		return -1;
+	}
 
 	if (broken > 0) {
 		if (print_colored(colors, colors->directory, path, broken, file) != 0) {
diff --git a/tests.sh b/tests.sh
index 409e1b2..b970547 100755
--- a/tests.sh
+++ b/tests.sh
@@ -618,6 +618,7 @@ bfs_tests=(
     test_color_no_stat
     test_color_L_no_stat
     test_color_star
+    test_color_ls
 
     test_execdir_plus
 
@@ -2105,6 +2106,30 @@ function test_color_star() {
     LS_COLORS="*" bfs_diff rainbow -color
 }
 
+function test_color_ls() {
+    rm -rf scratch/*
+    touchp scratch/foo/bar/baz
+    ln -s foo/bar/baz scratch/link
+    ln -s foo/bar/nowhere scratch/broken
+    ln -s foo/bar/nowhere/nothing scratch/nested
+    ln -s foo/bar/baz/qux scratch/notdir
+    ln -s scratch/foo/bar scratch/relative
+    ln -s /__bfs__/nowhere scratch/absolute
+
+    local EXPECTED="$TESTS/${FUNCNAME[0]}.out"
+    if [ "$UPDATE" ]; then
+        local ACTUAL="$EXPECTED"
+    else
+        local ACTUAL="$TMP/${FUNCNAME[0]}.out"
+    fi
+
+    LS_COLORS="or=01;31:" invoke_bfs scratch/{link,broken,nested,notdir,relative,absolute} -color -ls | sed 's/.* -> //' >"$ACTUAL"
+
+    if [ ! "$UPDATE" ]; then
+        diff -u "$EXPECTED" "$ACTUAL"
+    fi
+}
+
 function test_deep() {
     closefrom 4
 
diff --git a/tests/test_color_ls.out b/tests/test_color_ls.out
new file mode 100644
index 0000000..59a791a
--- /dev/null
+++ b/tests/test_color_ls.out
@@ -0,0 +1,6 @@
+foo/bar/baz
+foo/bar/nowhere
+foo/bar/nowhere/nothing
+foo/bar/baz/qux
+scratch/foo/bar
+/__bfs__/nowhere
-- 
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