From 0c08e0d74fc7a92f0fe5f671797ebfe99f69424d Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Mon, 10 Nov 2014 09:36:36 -0800
Subject: [PATCH] Don't panic on unused overrides

This previously did a failing hashtable lookup when an `Option`-returning `get`
would suffice.
---
 src/cargo/ops/cargo_rustc/custom_build.rs | 12 +++++++-----
 tests/test_cargo_compile_custom_build.rs  | 24 +++++++++++++++++++++++
 2 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/src/cargo/ops/cargo_rustc/custom_build.rs b/src/cargo/ops/cargo_rustc/custom_build.rs
index 342f67e11..d4d945b51 100644
--- a/src/cargo/ops/cargo_rustc/custom_build.rs
+++ b/src/cargo/ops/cargo_rustc/custom_build.rs
@@ -212,11 +212,13 @@ impl BuildState {
             }
         }
         let mut outputs = HashMap::new();
-        for (name, output) in config.host.overrides.into_iter() {
-            outputs.insert((sources[name].clone(), KindHost), output);
-        }
-        for (name, output) in config.target.overrides.into_iter() {
-            outputs.insert((sources[name].clone(), KindTarget), output);
+        let i1 = config.host.overrides.into_iter().map(|p| (p, KindHost));
+        let i2 = config.target.overrides.into_iter().map(|p| (p, KindTarget));
+        for ((name, output), kind) in i1.chain(i2) {
+            match sources.get(&name) {
+                Some(id) => { outputs.insert((id.clone(), kind), output); }
+                None => {}
+            }
         }
         BuildState { outputs: Mutex::new(outputs) }
     }
diff --git a/tests/test_cargo_compile_custom_build.rs b/tests/test_cargo_compile_custom_build.rs
index cd143bc9c..deec359fa 100644
--- a/tests/test_cargo_compile_custom_build.rs
+++ b/tests/test_cargo_compile_custom_build.rs
@@ -297,6 +297,30 @@ test!(overrides_and_links {
 ", compiling = COMPILING, running = RUNNING).as_slice()));
 })
 
+test!(unused_overrides {
+    let (_, target) = ::cargo::ops::rustc_version().unwrap();
+
+    let p = project("foo")
+        .file("Cargo.toml", r#"
+            [project]
+            name = "foo"
+            version = "0.5.0"
+            authors = []
+            build = "build.rs"
+        "#)
+        .file("src/lib.rs", "")
+        .file("build.rs", "fn main() {}")
+        .file(".cargo/config", format!(r#"
+            [target.{}.foo]
+            rustc-flags = "-L foo -L bar"
+            foo = "bar"
+            bar = "baz"
+        "#, target).as_slice());
+
+    assert_that(p.cargo_process("build").arg("-v"),
+                execs().with_status(0));
+})
+
 test!(links_passes_env_vars {
     let p = project("foo")
         .file("Cargo.toml", r#"
-- 
2.30.2