fish: fails to tilde expand '~' when $HOME env is unset (RHBZ#617440).

This also adds a regression test.

fish/tilde.c

@@ -28,8 +28,9 @@
 
 #include "fish.h"
 
-static char *expand_home (const char *);
+static char *expand_home (char *orig, const char *append);
 static const char *find_home_for_username (const char *, size_t);
+static const char *find_home_for_current_user (void);
 
 /* This is called from the script loop if we find a candidate for
  * ~username (tilde-expansion).
@@ -39,13 +40,11 @@ try_tilde_expansion (char *str)
 {
   assert (str[0] == '~');
 
-  /* Expand current user's home directory.  By simple experimentation
-   * I found out that bash always uses $HOME.
-   */
+  /* Expand "~" to current user's home directory. */
   if (str[1] == '\0')		/* ~ */
-    return expand_home (NULL);
+    return expand_home (str, NULL);
   else if (str[1] == '/')	/* ~/... */
-    return expand_home (&str[1]);
+    return expand_home (str, &str[1]);
 
   /* Try expanding the part up to the following '\0' or '/' as a
    * username from the password file.
@@ -76,14 +75,21 @@ try_tilde_expansion (char *str)
 
 /* Return $HOME + append string. */
 static char *
-expand_home (const char *append)
+expand_home (char *orig, const char *append)
 {
   const char *home;
   int len;
   char *str;
 
   home = getenv ("HOME");
-  if (!home) home = "~";
+  if (!home) {
+    /* $HOME not set, bash can look up the current user in the
+     * password file and find their home that way.  (RHBZ#617440).
+     */
+    home = find_home_for_current_user ();
+    if (!home)
+      return orig;
+  }
 
   len = strlen (home) + (append ? strlen (append) : 0) + 1;
   str = malloc (len);
@@ -116,3 +122,18 @@ find_home_for_username (const char *username, size_t ulen)
 
   return NULL;
 }
+
+static const char *
+find_home_for_current_user (void)
+{
+  struct passwd *pw;
+  uid_t euid = geteuid ();
+
+  setpwent ();
+  while ((pw = getpwent ()) != NULL) {
+    if (pw->pw_uid == euid)
+      return pw->pw_dir;
+  }
+
+  return NULL;
+}

regressions/Makefile.am

@@ -38,6 +38,7 @@ TESTS = \
 	test-find0.sh \
 	test-guestfish-a.sh \
 	test-guestfish-d.sh \
+	test-guestfish-tilde.sh \
 	test-launch-race.pl \
 	test-luks.sh \
 	test-lvm-filtering.sh \

regressions/test-guestfish-tilde.sh

@@ -0,0 +1,70 @@
+#!/bin/bash -
+# libguestfs
+# Copyright (C) 2011 Red Hat Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+# Test guestfish tilde expansion.
+# RHBZ#617440 guestfish: fails to tilde expand '~' when the $HOME env is unset
+# RHBZ#511372 guestfish doesn't understand '~' in filenames
+# and multiple other fixes to tilde handling.
+
+set -e
+
+# Don't rely on $HOME being set when this script is called.
+HOME=$(pwd)
+export HOME
+
+if [ `echo 'echo ~' | ../fish/guestfish` != "$HOME" ]; then
+    echo "$0: failed: did not expand ~ correctly"
+    exit 1
+fi
+
+if [ `echo 'echo ~/foo' | ../fish/guestfish` != "$HOME/foo" ]; then
+    echo "$0: failed: did not expand ~/foo correctly"
+    exit 1
+fi
+
+# We can be reasonably sure that the root user will always exist and
+# should have a home directory.
+root="$(echo ~root)"
+
+if [ `echo 'echo ~root' | ../fish/guestfish` != "$root" ]; then
+    echo "$0: failed: did not expand ~root correctly"
+    exit 1
+fi
+
+if [ `echo 'echo ~root/foo' | ../fish/guestfish` != "$root/foo" ]; then
+    echo "$0: failed: did not expand ~root/foo correctly"
+    exit 1
+fi
+
+# RHBZ#617440
+unset HOME
+home="$(echo ~)"
+
+if [ `echo 'echo ~' | ../fish/guestfish` != "$home" ]; then
+    echo "$0: failed: did not expand ~ correctly when \$HOME unset"
+    exit 1
+fi
+
+if [ `echo 'echo ~/foo' | ../fish/guestfish` != "$home/foo" ]; then
+    echo "$0: failed: did not expand ~/foo correctly when \$HOME unset"
+    exit 1
+fi
+
+# Setting $HOME to pwd above causes guestfish to create a history
+# file.  Remove it.
+rm -f .guestfish