From a42be8589a0b380da18a78da4c81205ff8086243 Mon Sep 17 00:00:00 2001
From: Cameron Steffen <cam.steffen94@gmail.com>
Date: Fri, 5 Feb 2021 16:28:13 -0600
Subject: [PATCH] Fix vec_init_then_push FP

---
 clippy_lints/src/vec_init_then_push.rs |  5 ++++-
 tests/ui/vec_init_then_push.rs         | 25 +++++++++++++++++++++++++
 tests/ui/vec_init_then_push.stderr     |  2 +-
 3 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/clippy_lints/src/vec_init_then_push.rs b/clippy_lints/src/vec_init_then_push.rs
index 4768cb4830b8..8d111f98add9 100644
--- a/clippy_lints/src/vec_init_then_push.rs
+++ b/clippy_lints/src/vec_init_then_push.rs
@@ -83,8 +83,11 @@ impl VecPushSearcher {
 }
 
 impl LateLintPass<'_> for VecInitThenPush {
-    fn check_local(&mut self, cx: &LateContext<'tcx>, local: &'tcx Local<'tcx>) {
+    fn check_block(&mut self, _: &LateContext<'tcx>, _: &'tcx Block<'tcx>) {
         self.searcher = None;
+    }
+
+    fn check_local(&mut self, cx: &LateContext<'tcx>, local: &'tcx Local<'tcx>) {
         if_chain! {
             if !in_external_macro(cx.sess(), local.span);
             if let Some(init) = local.init;
diff --git a/tests/ui/vec_init_then_push.rs b/tests/ui/vec_init_then_push.rs
index 642ce5040096..5099aad83bcb 100644
--- a/tests/ui/vec_init_then_push.rs
+++ b/tests/ui/vec_init_then_push.rs
@@ -12,10 +12,35 @@ fn main() {
     cap_err.push(0);
     cap_err.push(1);
     cap_err.push(2);
+    if true {
+        // don't include this one
+        cap_err.push(3);
+    }
 
     let mut cap_ok = Vec::with_capacity(10);
     cap_ok.push(0);
 
     new_err = Vec::new();
     new_err.push(0);
+
+    let mut vec = Vec::new();
+    // control flow at block final expression
+    if true {
+        // no lint
+        vec.push(1);
+    }
+}
+
+pub fn no_lint() -> Vec<i32> {
+    let mut p = Some(1);
+    let mut vec = Vec::new();
+    loop {
+        match p {
+            None => return vec,
+            Some(i) => {
+                vec.push(i);
+                p = None;
+            },
+        }
+    }
 }
diff --git a/tests/ui/vec_init_then_push.stderr b/tests/ui/vec_init_then_push.stderr
index 819ed47d0991..9ec3e10e6247 100644
--- a/tests/ui/vec_init_then_push.stderr
+++ b/tests/ui/vec_init_then_push.stderr
@@ -24,7 +24,7 @@ LL | |     cap_err.push(2);
    | |____________________^ help: consider using the `vec![]` macro: `let mut cap_err = vec![..];`
 
 error: calls to `push` immediately after creation
-  --> $DIR/vec_init_then_push.rs:19:5
+  --> $DIR/vec_init_then_push.rs:23:5
    |
 LL | /     new_err = Vec::new();
 LL | |     new_err.push(0);