Make if_not_else lint Allow by default (fixes #859)

README.md

@@ -61,7 +61,7 @@ name
 [for_loop_over_option](https://github.com/Manishearth/rust-clippy/wiki#for_loop_over_option)                         | warn    | for-looping over an `Option`, which is more clearly expressed as an `if let`
 [for_loop_over_result](https://github.com/Manishearth/rust-clippy/wiki#for_loop_over_result)                         | warn    | for-looping over a `Result`, which is more clearly expressed as an `if let`
 [identity_op](https://github.com/Manishearth/rust-clippy/wiki#identity_op)                                           | warn    | using identity operations, e.g. `x + 0` or `y / 1`
-[if_not_else](https://github.com/Manishearth/rust-clippy/wiki#if_not_else)                                           | warn    | finds if branches that could be swapped so no negation operation is necessary on the condition
+[if_not_else](https://github.com/Manishearth/rust-clippy/wiki#if_not_else)                                           | allow   | finds if branches that could be swapped so no negation operation is necessary on the condition
 [if_same_then_else](https://github.com/Manishearth/rust-clippy/wiki#if_same_then_else)                               | warn    | if with the same *then* and *else* blocks
 [ifs_same_cond](https://github.com/Manishearth/rust-clippy/wiki#ifs_same_cond)                                       | warn    | consecutive `ifs` with the same condition
 [indexing_slicing](https://github.com/Manishearth/rust-clippy/wiki#indexing_slicing)                                 | allow   | indexing/slicing usage

src/if_not_else.rs

@@ -14,7 +14,7 @@ use utils::span_help_and_lint;
 ///
 /// **Example:** if !v.is_empty() { a() } else { b() }
 declare_lint! {
-    pub IF_NOT_ELSE, Warn,
+    pub IF_NOT_ELSE, Allow,
     "finds if branches that could be swapped so no negation operation is necessary on the condition"
 }
 

src/lib.rs

@@ -237,6 +237,7 @@ pub fn plugin_registrar(reg: &mut Registry) {
         array_indexing::INDEXING_SLICING,
         booleans::NONMINIMAL_BOOL,
         enum_glob_use::ENUM_GLOB_USE,
+        if_not_else::IF_NOT_ELSE,
         matches::SINGLE_MATCH_ELSE,
         methods::OPTION_UNWRAP_USED,
         methods::RESULT_UNWRAP_USED,
@@ -289,7 +290,6 @@ pub fn plugin_registrar(reg: &mut Registry) {
         formatting::SUSPICIOUS_ELSE_FORMATTING,
         functions::TOO_MANY_ARGUMENTS,
         identity_op::IDENTITY_OP,
-        if_not_else::IF_NOT_ELSE,
         items_after_statements::ITEMS_AFTER_STATEMENTS,
         len_zero::LEN_WITHOUT_IS_EMPTY,
         len_zero::LEN_ZERO,

tests/compile-fail/entry.rs

@@ -1,6 +1,6 @@
 #![feature(plugin)]
 #![plugin(clippy)]
-#![allow(unused, if_not_else)]
+#![allow(unused)]
 
 #![deny(map_entry)]
 

tests/compile-fail/if_not_else.rs

@@ -1,6 +1,7 @@
 #![feature(plugin)]
 #![plugin(clippy)]
 #![deny(clippy)]
+#![deny(if_not_else)]
 
 fn bla() -> bool { unimplemented!() }