[libgudev/benzea/fix-newline-stripping: 1/2] gudev: Fix newline stripping by always reading using udev

[Benjamin Berg <bberg src gnome org>]

commit 71b2fda04dd71c637361e8ead103980ad6f27ed5
Author: Benjamin Berg <bberg redhat com>
Date:   Mon May 30 16:52:36 2022 +0200

    gudev: Fix newline stripping by always reading using udev
    
    libudev will strip trailing newline characters ("\r\n") when reading
    sysfs attributes. The uncached reading functions however bypassed the
    udev mechanism unnecessarily and then added their own cache on top.
    
    Setting the value to NULL clears the internal cache in systemd. As such,
    we can simply do this and then fall back to the normal implementation to
    implement the _uncached version of the sysfs attribute getters.

 gudev/gudevdevice.c | 106 +++++++---------------------------------------------
 1 file changed, 13 insertions(+), 93 deletions(-)
---
diff --git a/gudev/gudevdevice.c b/gudev/gudevdevice.c
index 38473dd..112c89e 100644
--- a/gudev/gudevdevice.c
+++ b/gudev/gudevdevice.c
@@ -78,7 +78,6 @@ struct _GUdevDevicePrivate
   gchar **tags;
   GHashTable *prop_strvs;
   GHashTable *sysfs_attr_strvs;
-  GHashTable *sysfs_attr;
 };
 
 G_DEFINE_TYPE_WITH_CODE (GUdevDevice, g_udev_device, G_TYPE_OBJECT, G_ADD_PRIVATE(GUdevDevice))
@@ -102,9 +101,6 @@ g_udev_device_finalize (GObject *object)
   if (device->priv->sysfs_attr_strvs != NULL)
     g_hash_table_unref (device->priv->sysfs_attr_strvs);
 
-  if (device->priv->sysfs_attr != NULL)
-    g_hash_table_unref (device->priv->sysfs_attr);
-
   if (G_OBJECT_CLASS (g_udev_device_parent_class)->finalize != NULL)
     (* G_OBJECT_CLASS (g_udev_device_parent_class)->finalize) (object);
 }
@@ -131,10 +127,6 @@ _g_udev_device_new (struct udev_device *udevice)
 
   device =  G_UDEV_DEVICE (g_object_new (G_UDEV_TYPE_DEVICE, NULL));
   device->priv->udevice = udev_device_ref (udevice);
-  device->priv->sysfs_attr = g_hash_table_new_full (g_str_hash,
-                                                    g_str_equal,
-                                                    g_free,
-                                                    g_free);
 
   return device;
 }
@@ -773,14 +765,8 @@ const gchar *
 g_udev_device_get_sysfs_attr (GUdevDevice  *device,
                               const gchar  *name)
 {
-  const char *attr;
-
   g_return_val_if_fail (G_UDEV_IS_DEVICE (device), NULL);
   g_return_val_if_fail (name != NULL, NULL);
-
-  attr = g_hash_table_lookup (device->priv->sysfs_attr, name);
-  if (attr)
-    return attr;
   return udev_device_get_sysattr_value (device->priv->udevice, name);
 }
 
@@ -1030,18 +1016,11 @@ const gchar *
 g_udev_device_get_sysfs_attr_uncached (GUdevDevice  *device,
                                        const gchar  *name)
 {
-  g_autofree char *path = NULL;
-  char *contents = NULL;
-
   g_return_val_if_fail (G_UDEV_IS_DEVICE (device), NULL);
   g_return_val_if_fail (name != NULL, NULL);
 
-  path = g_build_filename (udev_device_get_syspath (device->priv->udevice), name, NULL);
-  if (!g_file_get_contents (path, &contents, NULL, NULL))
-    return NULL;
-  g_hash_table_insert (device->priv->sysfs_attr, g_strdup (name), contents);
-
-  return contents;
+  udev_device_set_sysattr_value (device->priv->udevice, name, NULL);
+  return g_udev_device_get_sysfs_attr (device, name);
 }
 
 /**
@@ -1060,20 +1039,11 @@ gint
 g_udev_device_get_sysfs_attr_as_int_uncached (GUdevDevice  *device,
                                               const gchar  *name)
 {
-  gint result;
-  const gchar *s;
-
   g_return_val_if_fail (G_UDEV_IS_DEVICE (device), 0);
   g_return_val_if_fail (name != NULL, 0);
 
-  result = 0;
-  s = g_udev_device_get_sysfs_attr_uncached (device, name);
-  if (s == NULL)
-    goto out;
-
-  result = strtol (s, NULL, 0);
-out:
-  return result;
+  udev_device_set_sysattr_value (device->priv->udevice, name, NULL);
+  return g_udev_device_get_sysfs_attr_as_int (device, name);
 }
 
 /**
@@ -1092,20 +1062,11 @@ guint64
 g_udev_device_get_sysfs_attr_as_uint64_uncached (GUdevDevice  *device,
                                                  const gchar  *name)
 {
-  guint64 result;
-  const gchar *s;
-
   g_return_val_if_fail (G_UDEV_IS_DEVICE (device), 0);
   g_return_val_if_fail (name != NULL, 0);
 
-  result = 0;
-  s = g_udev_device_get_sysfs_attr_uncached (device, name);
-  if (s == NULL)
-    goto out;
-
-  result = g_ascii_strtoull (s, NULL, 0);
-out:
-  return result;
+  udev_device_set_sysattr_value (device->priv->udevice, name, NULL);
+  return g_udev_device_get_sysfs_attr_as_uint64 (device, name);
 }
 
 /**
@@ -1124,20 +1085,11 @@ gdouble
 g_udev_device_get_sysfs_attr_as_double_uncached (GUdevDevice  *device,
                                                  const gchar  *name)
 {
-  gdouble result;
-  const gchar *s;
-
   g_return_val_if_fail (G_UDEV_IS_DEVICE (device), 0.0);
   g_return_val_if_fail (name != NULL, 0.0);
 
-  result = 0.0;
-  s = g_udev_device_get_sysfs_attr_uncached (device, name);
-  if (s == NULL)
-    goto out;
-
-  result = g_ascii_strtod (s, NULL);
-out:
-  return result;
+  udev_device_set_sysattr_value (device->priv->udevice, name, NULL);
+  return g_udev_device_get_sysfs_attr_as_double (device, name);
 }
 
 /**
@@ -1157,29 +1109,11 @@ gboolean
 g_udev_device_get_sysfs_attr_as_boolean_uncached (GUdevDevice  *device,
                                                   const gchar  *name)
 {
-  gboolean result;
-  const gchar *raw;
-  g_autofree char *truncated = NULL;
-  const char *s;
-
   g_return_val_if_fail (G_UDEV_IS_DEVICE (device), FALSE);
   g_return_val_if_fail (name != NULL, FALSE);
 
-  result = FALSE;
-  raw = g_udev_device_get_sysfs_attr_uncached (device, name);
-  if (raw == NULL)
-    goto out;
-
-  truncated = truncate_at_linefeed (raw);
-  s = truncated ?: raw;
-  if (strcmp (s, "1") == 0 ||
-      g_ascii_strcasecmp (s, "true") == 0 ||
-      g_ascii_strcasecmp (s, "y") == 0) {
-    result = TRUE;
-  }
-
- out:
-  return result;
+  udev_device_set_sysattr_value (device->priv->udevice, name, NULL);
+  return g_udev_device_get_sysfs_attr_as_boolean (device, name);
 }
 
 /**
@@ -1204,27 +1138,13 @@ const gchar * const *
 g_udev_device_get_sysfs_attr_as_strv_uncached (GUdevDevice  *device,
                                                const gchar  *name)
 {
-  gchar **result;
-  const gchar *s;
-
   g_return_val_if_fail (G_UDEV_IS_DEVICE (device), NULL);
   g_return_val_if_fail (name != NULL, NULL);
 
-  result = NULL;
-  s = g_udev_device_get_sysfs_attr_uncached (device, name);
-  if (s == NULL)
-    goto out;
+  g_hash_table_remove (device->priv->sysfs_attr_strvs, name);
 
-  result = split_at_whitespace (s);
-  if (result == NULL)
-    goto out;
-
-  if (device->priv->sysfs_attr_strvs == NULL)
-    device->priv->sysfs_attr_strvs = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, 
(GDestroyNotify) g_strfreev);
-  g_hash_table_insert (device->priv->sysfs_attr_strvs, g_strdup (name), result);
-
-out:
-  return (const gchar* const *) result;
+  udev_device_set_sysattr_value (device->priv->udevice, name, NULL);
+  return g_udev_device_get_sysfs_attr_as_strv (device, name);
 }
 
 /**