Prefer $HOME when looking up the current user's home directory.

When we need to identify the home directory on non-Windows, first
consult getenv("HOME").  If that's empty or unset, fall back
on our previous method of checking the <pwd.h> database.

Preferring $HOME allows the user to intentionally point at some
other directory, and it seems to be in line with the behavior of
most other utilities.  However, we shouldn't rely on it completely,
as $HOME is likely to be unset when running as a daemon.

Anders Kaseorg

Discussion: https://postgr.es/m/1634252654444.90107@mit.edu

1 files changed, 19 insertions, 12 deletions

diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index 053332e7af5..f5904748553 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -558,19 +558,25 @@ exec_command_cd(PsqlScanState scan_state, bool active_branch, const char *cmd)
 		else
 		{
 #ifndef WIN32
-			struct passwd *pw;
-			uid_t		user_id = geteuid();
-
-			errno = 0;			/* clear errno before call */
-			pw = getpwuid(user_id);
-			if (!pw)
+			/* This should match get_home_path() */
+			dir = getenv("HOME");
+			if (dir == NULL || dir[0] == '\0')
 			{
-				pg_log_error("could not get home directory for user ID %ld: %s",
-							 (long) user_id,
-							 errno ? strerror(errno) : _("user does not exist"));
-				exit(EXIT_FAILURE);
+				uid_t		user_id = geteuid();
+				struct passwd *pw;
+
+				errno = 0;		/* clear errno before call */
+				pw = getpwuid(user_id);
+				if (pw)
+					dir = pw->pw_dir;
+				else
+				{
+					pg_log_error("could not get home directory for user ID %ld: %s",
+								 (long) user_id,
+								 errno ? strerror(errno) : _("user does not exist"));
+					success = false;
+				}
 			}
-			dir = pw->pw_dir;
 #else							/* WIN32 */
 
 			/*
@@ -581,7 +587,8 @@ exec_command_cd(PsqlScanState scan_state, bool active_branch, const char *cmd)
 #endif							/* WIN32 */
 		}
 
-		if (chdir(dir) == -1)
+		if (success &&
+			chdir(dir) < 0)
 		{
 			pg_log_error("\\%s: could not change directory to \"%s\": %m",
 						 cmd, dir);