Auto merge of #9214 - Jarcho:assign_op_prim, r=Manishearth

Check `assign_op_pattern` for conflicting borrows

fixes #9180

changelog: [`assign_op_pattern`](https://rust-lang.github.io/rust-clippy/master/#assign_op_pattern): Don't lint when the suggestion would cause borrowck errors.

3 files changed, 44 insertions, 10 deletions

diff --git a/tests/ui/assign_ops.fixed b/tests/ui/assign_ops.fixed
index 52b1b3afe16..da034b51cfd 100644
--- a/tests/ui/assign_ops.fixed
+++ b/tests/ui/assign_ops.fixed
@@ -1,5 +1,7 @@
 // run-rustfix
 
+use core::num::Wrapping;
+
 #[allow(dead_code, unused_assignments)]
 #[warn(clippy::assign_op_pattern)]
 fn main() {
@@ -18,4 +20,13 @@ fn main() {
     a = 6 << a;
     let mut s = String::new();
     s += "bla";
+
+    // Issue #9180
+    let mut a = Wrapping(0u32);
+    a += Wrapping(1u32);
+    let mut v = vec![0u32, 1u32];
+    v[0] += v[1];
+    let mut v = vec![Wrapping(0u32), Wrapping(1u32)];
+    v[0] = v[0] + v[1];
+    let _ = || v[0] = v[0] + v[1];
 }
diff --git a/tests/ui/assign_ops.rs b/tests/ui/assign_ops.rs
index 527a46b2c2b..337bb02c8a6 100644
--- a/tests/ui/assign_ops.rs
+++ b/tests/ui/assign_ops.rs
@@ -1,5 +1,7 @@
 // run-rustfix
 
+use core::num::Wrapping;
+
 #[allow(dead_code, unused_assignments)]
 #[warn(clippy::assign_op_pattern)]
 fn main() {
@@ -18,4 +20,13 @@ fn main() {
     a = 6 << a;
     let mut s = String::new();
     s = s + "bla";
+
+    // Issue #9180
+    let mut a = Wrapping(0u32);
+    a = a + Wrapping(1u32);
+    let mut v = vec![0u32, 1u32];
+    v[0] = v[0] + v[1];
+    let mut v = vec![Wrapping(0u32), Wrapping(1u32)];
+    v[0] = v[0] + v[1];
+    let _ = || v[0] = v[0] + v[1];
 }
diff --git a/tests/ui/assign_ops.stderr b/tests/ui/assign_ops.stderr
index 3486bd8da4d..63a938ab4b4 100644
--- a/tests/ui/assign_ops.stderr
+++ b/tests/ui/assign_ops.stderr
@@ -1,5 +1,5 @@
 error: manual implementation of an assign operation
-  --> $DIR/assign_ops.rs:7:5
+  --> $DIR/assign_ops.rs:9:5
    |
 LL |     a = a + 1;
    |     ^^^^^^^^^ help: replace it with: `a += 1`
@@ -7,52 +7,64 @@ LL |     a = a + 1;
    = note: `-D clippy::assign-op-pattern` implied by `-D warnings`
 
 error: manual implementation of an assign operation
-  --> $DIR/assign_ops.rs:8:5
+  --> $DIR/assign_ops.rs:10:5
    |
 LL |     a = 1 + a;
    |     ^^^^^^^^^ help: replace it with: `a += 1`
 
 error: manual implementation of an assign operation
-  --> $DIR/assign_ops.rs:9:5
+  --> $DIR/assign_ops.rs:11:5
    |
 LL |     a = a - 1;
    |     ^^^^^^^^^ help: replace it with: `a -= 1`
 
 error: manual implementation of an assign operation
-  --> $DIR/assign_ops.rs:10:5
+  --> $DIR/assign_ops.rs:12:5
    |
 LL |     a = a * 99;
    |     ^^^^^^^^^^ help: replace it with: `a *= 99`
 
 error: manual implementation of an assign operation
-  --> $DIR/assign_ops.rs:11:5
+  --> $DIR/assign_ops.rs:13:5
    |
 LL |     a = 42 * a;
    |     ^^^^^^^^^^ help: replace it with: `a *= 42`
 
 error: manual implementation of an assign operation
-  --> $DIR/assign_ops.rs:12:5
+  --> $DIR/assign_ops.rs:14:5
    |
 LL |     a = a / 2;
    |     ^^^^^^^^^ help: replace it with: `a /= 2`
 
 error: manual implementation of an assign operation
-  --> $DIR/assign_ops.rs:13:5
+  --> $DIR/assign_ops.rs:15:5
    |
 LL |     a = a % 5;
    |     ^^^^^^^^^ help: replace it with: `a %= 5`
 
 error: manual implementation of an assign operation
-  --> $DIR/assign_ops.rs:14:5
+  --> $DIR/assign_ops.rs:16:5
    |
 LL |     a = a & 1;
    |     ^^^^^^^^^ help: replace it with: `a &= 1`
 
 error: manual implementation of an assign operation
-  --> $DIR/assign_ops.rs:20:5
+  --> $DIR/assign_ops.rs:22:5
    |
 LL |     s = s + "bla";
    |     ^^^^^^^^^^^^^ help: replace it with: `s += "bla"`
 
-error: aborting due to 9 previous errors
+error: manual implementation of an assign operation
+  --> $DIR/assign_ops.rs:26:5
+   |
+LL |     a = a + Wrapping(1u32);
+   |     ^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `a += Wrapping(1u32)`
+
+error: manual implementation of an assign operation
+  --> $DIR/assign_ops.rs:28:5
+   |
+LL |     v[0] = v[0] + v[1];
+   |     ^^^^^^^^^^^^^^^^^^ help: replace it with: `v[0] += v[1]`
+
+error: aborting due to 11 previous errors