unset variable with ENV{VAR}=""

3 files changed, 32 insertions, 6 deletions

diff --git a/udev.h b/udev.h
index 5bd0e301c6..6ef95133d5 100644
--- a/udev.h
+++ b/udev.h
@@ -137,6 +137,7 @@ struct name_entry {
 extern int log_priority(const char *priority);
 extern char *name_list_add(struct list_head *name_list, const char *name, int sort);
 extern char *name_list_key_add(struct list_head *name_list, const char *key, const char *value);
+extern int name_list_key_remove(struct list_head *name_list, const char *key);
 extern void name_list_cleanup(struct list_head *name_list);
 extern int add_matching_files(struct list_head *name_list, const char *dirname, const char *suffix);
 extern uid_t lookup_user(const char *user);
diff --git a/udev_rules.c b/udev_rules.c
index 6bd28ad4b7..61b39b45c8 100644
--- a/udev_rules.c
+++ b/udev_rules.c
@@ -831,18 +831,23 @@ try_parent:
 			char temp_value[NAME_SIZE];
 			const char *key_name = key_pair_name(rule, pair);
 			const char *value = key_val(rule, &pair->key);
-			char *key_value;
 
 			/* make sure we don't write to the same string we possibly read from */
 			strlcpy(temp_value, value, sizeof(temp_value));
 			udev_rules_apply_format(udev, temp_value, NAME_SIZE);
 
-			key_value = name_list_key_add(&udev->env_list, key_name, temp_value);
-			if (key_value == NULL)
-				break;
+			if (temp_value[0] == '\0') {
+				name_list_key_remove(&udev->env_list, key_name);
+				unsetenv(key_name);
+				info("unset ENV '%s'", key_name);
+			} else {
+				char *key_value = name_list_key_add(&udev->env_list, key_name, temp_value);
 
-			putenv(key_value);
-			dbg("export ENV '%s'", key_value);
+				if (key_value == NULL)
+					break;
+				putenv(key_value);
+				info("set ENV '%s'", key_value);
+			}
 		}
 	}
 
diff --git a/udev_utils.c b/udev_utils.c
index e892012132..6d646b0ee6 100644
--- a/udev_utils.c
+++ b/udev_utils.c
@@ -110,6 +110,26 @@ char *name_list_key_add(struct list_head *name_list, const char *key, const char
 	return new_name->name;
 }
 
+int name_list_key_remove(struct list_head *name_list, const char *key)
+{
+	struct name_entry *name_loop;
+	struct name_entry *temp_loop;
+	size_t keylen = strlen(key);
+	int retval = 0;
+
+	list_for_each_entry_safe(name_loop, temp_loop, name_list, node) {
+		if (strncmp(name_loop->name, key, keylen) != 0)
+			continue;
+		if (name_loop->name[keylen] != '=')
+			continue;
+		list_del(&name_loop->node);
+		free(name_loop);
+		retval = 1;
+		break;
+	}
+	return retval;
+}
+
 void name_list_cleanup(struct list_head *name_list)
 {
 	struct name_entry *name_loop;