From fc98276e1401366fd91a437af3e7fa5f1471f94e Mon Sep 17 00:00:00 2001
From: Tavian Barnes <tavianator@tavianator.com>
Date: Mon, 21 Nov 2016 14:40:46 -0500
Subject: Fix -execdir for /

---
 eval.c              | 17 ++++++++++++-----
 tests.sh            | 16 +++++++++++++++-
 tests/test_0098.out |  1 +
 tests/test_0099.out |  1 +
 tests/test_0100.out |  1 +
 5 files changed, 30 insertions(+), 6 deletions(-)
 create mode 100644 tests/test_0098.out
 create mode 100644 tests/test_0099.out
 create mode 100644 tests/test_0100.out

diff --git a/eval.c b/eval.c
index 16c4dac..4fc91cc 100644
--- a/eval.c
+++ b/eval.c
@@ -261,14 +261,21 @@ bool eval_delete(const struct expr *expr, struct eval_state *state) {
 	return true;
 }
 
+static const char *exec_slash = "/";
+
 static const char *exec_format_path(const struct expr *expr, const struct BFTW *ftwbuf) {
 	if (!(expr->exec_flags & EXEC_CHDIR)) {
 		return ftwbuf->path;
 	}
 
-	// For compatibility with GNU find, use './name' instead of just 'name'
 	const char *name = ftwbuf->path + ftwbuf->nameoff;
 
+	if (name[0] == '/') {
+		// Must be the root path ("/", "//", etc.), which we canonicalize
+		return exec_slash;
+	}
+
+	// For compatibility with GNU find, use './name' instead of just 'name'
 	char *path = dstralloc(2 + strlen(name));
 	if (!path) {
 		perror("dstralloc()");
@@ -292,7 +299,7 @@ err:
 }
 
 static void exec_free_path(const char *path, const struct BFTW *ftwbuf) {
-	if (path != ftwbuf->path) {
+	if (path != ftwbuf->path && path != exec_slash) {
 		dstrfree((char *)path);
 	}
 }
@@ -388,12 +395,12 @@ static void exec_chdir(const struct BFTW *ftwbuf) {
 	while (end > path && end[-1] != '/') {
 		--end;
 	}
-	if (end == path) {
+	if (end > path) {
+		*end = '\0';
+	} if (path[0] != '/') {
 		// The path is something like "foo", so we're already in the
 		// right directory
 		return;
-	} else {
-		*end = '\0';
 	}
 
 	if (chdir(path) != 0) {
diff --git a/tests.sh b/tests.sh
index ba731eb..3d3d10b 100755
--- a/tests.sh
+++ b/tests.sh
@@ -522,7 +522,21 @@ function test_0097() {
     (cd scratch && "$BFS" -delete)
 }
 
-for i in {1..97}; do
+function test_0098() {
+    bfs_diff / -maxdepth 0 -execdir pwd ';'
+}
+
+function test_0099() {
+    # Don't prepend ./ for absolute paths in -execdir
+    bfs_diff / -maxdepth 0 -execdir echo '{}' ';'
+}
+
+function test_0100() {
+    # // is canonicalized to /
+    bfs_diff // -maxdepth 0 -execdir echo '{}' ';'
+}
+
+for i in {1..100}; do
     test="test_$(printf '%04d' $i)"
 
     if [ -t 1 ]; then
diff --git a/tests/test_0098.out b/tests/test_0098.out
new file mode 100644
index 0000000..b498fd4
--- /dev/null
+++ b/tests/test_0098.out
@@ -0,0 +1 @@
+/
diff --git a/tests/test_0099.out b/tests/test_0099.out
new file mode 100644
index 0000000..b498fd4
--- /dev/null
+++ b/tests/test_0099.out
@@ -0,0 +1 @@
+/
diff --git a/tests/test_0100.out b/tests/test_0100.out
new file mode 100644
index 0000000..b498fd4
--- /dev/null
+++ b/tests/test_0100.out
@@ -0,0 +1 @@
+/
-- 
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