Use a stamp file to protect against corrupt checkouts

We already take this strategy for extracting tarballs from crates.io for
example, so this just applies the same strategy to checkouts of git repos.

Closes #1979

diff --git a/src/cargo/sources/git/utils.rs b/src/cargo/sources/git/utils.rs
index 51f69a6d27e893be49146dcba1421bee55a949f3..f51b9dc97b9f0bf3f6749ad89cb4a046c78b0d88 100644 (file)
--- a/src/cargo/sources/git/utils.rs
+++ b/src/cargo/sources/git/utils.rs
@@ -1,6 +1,6 @@
 use std::fmt;
 use std::path::{Path, PathBuf};
-use std::fs;
+use std::fs::{self, File};
 
 use rustc_serialize::{Encodable, Encoder};
 use url::Url;
@@ -267,7 +267,10 @@ impl<'a> GitCheckout<'a> {
 
     fn is_fresh(&self) -> bool {
         match self.repo.revparse_single("HEAD") {
-            Ok(head) => head.id().to_string() == self.revision.to_string(),
+            Ok(ref head) if head.id() == self.revision.0 => {
+                // See comments in reset() for why we check this
+                fs::metadata(self.location.join(".cargo-ok")).is_ok()
+            }
             _ => false,
         }
     }
@@ -282,9 +285,20 @@ impl<'a> GitCheckout<'a> {
     }
 
     fn reset(&self) -> CargoResult<()> {
+        // If we're interrupted while performing this reset (e.g. we die because
+        // of a signal) Cargo needs to be sure to try to check out this repo
+        // again on the next go-round.
+        //
+        // To enable this we have a dummy file in our checkout, .cargo-ok, which
+        // if present means that the repo has been successfully reset and is
+        // ready to go. Hence if we start to do a reset, we make sure this file
+        // *doesn't* exist, and then once we're done we create the file.
+        let ok_file = self.location.join(".cargo-ok");
+        let _ = fs::remove_file(&ok_file);
         info!("reset {} to {}", self.repo.path().display(), self.revision);
         let object = try!(self.repo.find_object(self.revision.0, None));
         try!(self.repo.reset(&object, git2::ResetType::Hard, None));
+        try!(File::create(ok_file));
         Ok(())
     }
 

diff --git a/tests/test_cargo_compile.rs b/tests/test_cargo_compile.rs
index 62dfd76f2c2327bbe99c400c208c7b2f3dd7c145..482a6dee442516ad2c82db3bf0a2fa5436626568 100644 (file)
--- a/tests/test_cargo_compile.rs
+++ b/tests/test_cargo_compile.rs
@@ -1508,7 +1508,7 @@ test!(cargo_platform_specific_dependency {
                 execs().with_status(0));
 
     assert_that(&p.bin("foo"), existing_file());
-    assert_that(p.cargo_process("test"),
+    assert_that(p.cargo("test"),
                 execs().with_status(0));
 });