From ba35e9924e95c45f8ae536f453b9064740e49841 Mon Sep 17 00:00:00 2001
From: Andreas Gustafsson <source@isc.org>
Date: Mon, 16 Jul 2001 18:33:02 +0000
Subject: [PATCH] added isc_file_ischdiridempotent()

---
 lib/isc/include/isc/file.h |  9 ++++++++-
 lib/isc/unix/file.c        | 12 +++++++++++-
 lib/isc/win32/file.c       | 17 ++++++++++++++++-
 3 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/lib/isc/include/isc/file.h b/lib/isc/include/isc/file.h
index 3870ca238f..649fef4574 100644
--- a/lib/isc/include/isc/file.h
+++ b/lib/isc/include/isc/file.h
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: file.h,v 1.23 2001/07/16 17:22:16 gson Exp $ */
+/* $Id: file.h,v 1.24 2001/07/16 18:33:00 gson Exp $ */
 
 #ifndef ISC_FILE_H
 #define ISC_FILE_H 1
@@ -185,6 +185,13 @@ isc_file_iscurrentdir(const char *filename);
  * Return ISC_TRUE iff the given file name is the current directory (".").
  */
 
+isc_boolean_t
+isc_file_ischdiridempotent(const char *filename);
+/*
+ * Return ISC_TRUE if calling chdir(filename) multiple times will give
+ * the same result as calling it once.
+ */
+
 const char *
 isc_file_basename(const char *filename);
 /*
diff --git a/lib/isc/unix/file.c b/lib/isc/unix/file.c
index e599986e10..da00282812 100644
--- a/lib/isc/unix/file.c
+++ b/lib/isc/unix/file.c
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: file.c,v 1.37 2001/07/16 17:26:44 gson Exp $ */
+/* $Id: file.c,v 1.38 2001/07/16 18:33:01 gson Exp $ */
 
 #include <config.h>
 
@@ -261,6 +261,16 @@ isc_file_iscurrentdir(const char *filename) {
 	return (ISC_TF(filename[0] == '.' && filename[1] == '\0'));
 }
 
+isc_boolean_t
+isc_file_ischdiridempotent(const char *filename) {
+	REQUIRE(filename != NULL);
+	if (isc_file_isabsolute(filename))
+		return (ISC_TRUE);
+	if (isc_file_iscurrentdir(filename))
+		return (ISC_TRUE);
+	return (ISC_FALSE);
+}
+
 const char *
 isc_file_basename(const char *filename) {
 	char *s;
diff --git a/lib/isc/win32/file.c b/lib/isc/win32/file.c
index d1ef5d9a8f..d6335e297f 100644
--- a/lib/isc/win32/file.c
+++ b/lib/isc/win32/file.c
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: file.c,v 1.18 2001/07/16 17:22:17 gson Exp $ */
+/* $Id: file.c,v 1.19 2001/07/16 18:33:02 gson Exp $ */
 
 #include <config.h>
 
@@ -402,6 +402,21 @@ isc_file_iscurrentdir(const char *filename) {
 	return (ISC_TF(filename[0] == '.' && filename[1] == '\0'));
 }
 
+isc_boolean_t
+isc_file_ischdiridempotent(const char *filename) {
+	REQUIRE(filename != NULL);
+
+	if (isc_file_isabsolute(filename))
+		return (ISC_TRUE);
+	if (filename[0] == '\\')
+		return (ISC_TRUE);
+	if (filename[0] == '/')
+		return (ISC_TRUE);
+	if (isc_file_iscurrentdir(filename))
+		return (ISC_TRUE);
+	return (ISC_FALSE);
+}
+
 const char *
 isc_file_basename(const char *filename) {
 	char *s;