sh: Fix confusing behaviour if chdir succeeded but getcwd failed in cd -P.

If getcwd fails, do not treat this as an error, but print a warning and
unset PWD. This is similar to the behaviour when starting the shell in a
directory whose name cannot be determined.

1 files changed, 5 insertions, 2 deletions

diff --git a/bin/sh/cd.c b/bin/sh/cd.c
index cec7496..2ac4b10 100644
--- a/bin/sh/cd.c
+++ b/bin/sh/cd.c
@@ -219,10 +219,13 @@ cdphysical(char *dest)
 	char *p;
 
 	INTOFF;
-	if (chdir(dest) < 0 || (p = findcwd(NULL)) == NULL) {
+	if (chdir(dest) < 0) {
 		INTON;
 		return (-1);
 	}
+	p = findcwd(NULL);
+	if (p == NULL)
+		out2fmt_flush("cd: warning: failed to get name of current directory\n");
 	updatepwd(p);
 	INTON;
 	return (0);
@@ -304,7 +307,7 @@ updatepwd(char *dir)
 	if (prevdir)
 		ckfree(prevdir);
 	prevdir = curdir;
-	curdir = savestr(dir);
+	curdir = dir ? savestr(dir) : NULL;
 	setvar("PWD", curdir, VEXPORT);
 	setvar("OLDPWD", prevdir, VEXPORT);
 }