use allow-dirty option in cargo package to skip vcs checks

To avoid introducing another flag, this change uses the `--allow-dirty`
flag to skip checking for vcs information. This is logical because a
user that passes that flag is indicating to `cargo package` that they
do not care about the state of vcs at that time.

src/bin/cargo/commands/package.rs

@@ -23,10 +23,6 @@ pub fn cli() -> App {
             "allow-dirty",
             "Allow dirty working directories to be packaged",
         ))
-        .arg(opt(
-            "no-vcs",
-            "Ignore version control for packaging",
-        ))
         .arg_target_triple("Build for the target triple")
         .arg_target_dir()
         .arg_manifest_path()
@@ -43,7 +39,6 @@ pub fn exec(config: &mut Config, args: &ArgMatches) -> CliResult {
             list: args.is_present("list"),
             check_metadata: !args.is_present("no-metadata"),
             allow_dirty: args.is_present("allow-dirty"),
-            use_vcs: !args.is_present("no-vcs"),
             target: args.target(),
             jobs: args.jobs()?,
             registry: None,

src/cargo/ops/cargo_package.rs

@@ -24,7 +24,6 @@ pub struct PackageOpts<'cfg> {
     pub check_metadata: bool,
     pub allow_dirty: bool,
     pub verify: bool,
-    pub use_vcs: bool,
     pub jobs: Option<u32>,
     pub target: Option<String>,
     pub registry: Option<String>,
@@ -56,7 +55,7 @@ pub fn package(ws: &Workspace, opts: &PackageOpts) -> CargoResult<Option<FileLoc
     // Check (git) repository state, getting the current commit hash if not
     // dirty. This will `bail!` if dirty, unless allow_dirty. Produce json
     // info for any sha1 (HEAD revision) returned.
-    let vcs_info = if opts.use_vcs {
+    let vcs_info = if !opts.allow_dirty {
         check_repo_state(pkg, &src_files, &config, opts.allow_dirty)?
             .map(|h| json!({"git":{"sha1": h}}))
     } else {

src/cargo/ops/registry.rs

@@ -80,7 +80,6 @@ pub fn publish(ws: &Workspace, opts: &PublishOpts) -> CargoResult<()> {
             list: false,
             check_metadata: true,
             allow_dirty: opts.allow_dirty,
-            use_vcs: true,
             target: opts.target.clone(),
             jobs: opts.jobs,
             registry: opts.registry.clone(),