Fix false positive for wrong_self_convention

clippy_lints/src/methods.rs

@@ -1256,7 +1256,7 @@ impl Convention {
     fn check(&self, other: &str) -> bool {
         match *self {
             Convention::Eq(this) => this == other,
-            Convention::StartsWith(this) => other.starts_with(this),
+            Convention::StartsWith(this) => other.starts_with(this) && this != other,
         }
     }
 }

tests/compile-fail/wrong_self_convention.rs

@@ -45,4 +45,10 @@ impl Bar {
     pub fn to_i64(self) {} //~ERROR: methods called `to_*` usually take self by reference
     pub fn from_i64(self) {} //~ERROR: methods called `from_*` usually take no self
 
+    // test for false positives
+    fn as_(self) {}
+    fn into_(&self) {}
+    fn is_(self) {}
+    fn to_(self) {}
+    fn from_(self) {}
 }