Propagate existing VCS to subprojects

src/cargo/ops/cargo_new.rs

@@ -538,30 +538,44 @@ fn write_ignore_file(
 }
 
 /// Initializes the correct VCS system based on the provided config.
-fn init_vcs(path: &Path, vcs: VersionControl, config: &Config) -> CargoResult<()> {
+fn init_vcs(
+    path: &Path,
+    vcs: VersionControl,
+    config: &Config,
+    in_existing_vcs: bool,
+    explicit: bool,
+) -> CargoResult<()> {
     match vcs {
         VersionControl::Git => {
             if !path.join(".git").exists() {
                 // Temporary fix to work around bug in libgit2 when creating a
                 // directory in the root of a posix filesystem.
                 // See: https://github.com/libgit2/libgit2/issues/5130
                 paths::create_dir_all(path)?;
-                GitRepo::init(path, config.cwd())?;
+                if explicit || !in_existing_vcs {
+                    GitRepo::init(path, config.cwd())?;
+                }
             }
         }
         VersionControl::Hg => {
             if !path.join(".hg").exists() {
-                HgRepo::init(path, config.cwd())?;
+                if explicit || !in_existing_vcs {
+                    HgRepo::init(path, config.cwd())?;
+                }
             }
         }
         VersionControl::Pijul => {
             if !path.join(".pijul").exists() {
-                PijulRepo::init(path, config.cwd())?;
+                if explicit || !in_existing_vcs {
+                    PijulRepo::init(path, config.cwd())?;
+                }
             }
         }
         VersionControl::Fossil => {
             if !path.join(".fossil").exists() {
-                FossilRepo::init(path, config.cwd())?;
+                if explicit || !in_existing_vcs {
+                    FossilRepo::init(path, config.cwd())?;
+                }
             }
         }
         VersionControl::NoVcs => {
@@ -585,16 +599,25 @@ fn mk(config: &Config, opts: &MkOptions<'_>) -> CargoResult<()> {
         ignore.push("Cargo.lock", "glob:Cargo.lock");
     }
 
-    let vcs = opts.version_control.unwrap_or_else(|| {
-        let in_existing_vcs = existing_vcs_repo(path.parent().unwrap_or(path), config.cwd());
-        match (cfg.version_control, in_existing_vcs) {
-            (None, false) => VersionControl::Git,
-            (Some(opt), false) => opt,
-            (_, true) => VersionControl::NoVcs,
+    let existing_vcs = existing_vcs_repo(path.parent().unwrap_or(path), config.cwd());
+    let in_existing_vcs = existing_vcs != VersionControl::NoVcs;
+    let mut explicit = false;
+    let vcs = match opts.version_control {
+        Some(opt) => {
+            explicit = true;
+            opt
         }
-    });
+        None => match (cfg.version_control, in_existing_vcs) {
+            (None, false) => VersionControl::Git,
+            (Some(opt), _) => {
+                explicit = true;
+                opt
+            }
+            (None, true) => existing_vcs,
+        },
+    };
 
-    init_vcs(path, vcs, config)?;
+    init_vcs(path, vcs, config, in_existing_vcs, explicit)?;
     write_ignore_file(path, &ignore, vcs)?;
 
     let (author_name, email) = discover_author()?;

src/cargo/ops/fix.rs

@@ -52,7 +52,7 @@ use rustfix::diagnostics::Diagnostic;
 use rustfix::{self, CodeFix};
 
 use crate::core::Workspace;
-use crate::ops::{self, CompileOptions};
+use crate::ops::{self, CompileOptions, VersionControl};
 use crate::util::diagnostic_server::{Message, RustfixDiagnosticServer};
 use crate::util::errors::CargoResult;
 use crate::util::{self, paths};
@@ -146,7 +146,7 @@ fn check_version_control(opts: &FixOptions<'_>) -> CargoResult<()> {
         return Ok(());
     }
     let config = opts.compile_opts.config;
-    if !existing_vcs_repo(config.cwd(), config.cwd()) {
+    if VersionControl::NoVcs == existing_vcs_repo(config.cwd(), config.cwd()) {
         failure::bail!(
             "no VCS found for this package and `cargo fix` can potentially \
              perform destructive changes; if you'd like to suppress this \

src/cargo/util/vcs.rs

@@ -1,3 +1,4 @@
+use crate::ops::VersionControl;
 use crate::util::paths;
 use crate::util::{process, CargoResult};
 use git2;
@@ -8,7 +9,7 @@ use std::path::Path;
 // 1. We are in a git repo and the path to the new package is not an ignored
 //    path in that repo.
 // 2. We are in an HG repo.
-pub fn existing_vcs_repo(path: &Path, cwd: &Path) -> bool {
+pub fn existing_vcs_repo(path: &Path, cwd: &Path) -> VersionControl {
     fn in_git_repo(path: &Path, cwd: &Path) -> bool {
         if let Ok(repo) = GitRepo::discover(path, cwd) {
             // Don't check if the working directory itself is ignored.
@@ -22,7 +23,12 @@ pub fn existing_vcs_repo(path: &Path, cwd: &Path) -> bool {
         }
     }
 
-    in_git_repo(path, cwd) || HgRepo::discover(path, cwd).is_ok()
+    if in_git_repo(path, cwd) {
+        return VersionControl::Git;
+    } else if HgRepo::discover(path, cwd).is_ok() {
+        return VersionControl::Hg;
+    }
+    VersionControl::NoVcs
 }
 
 pub struct HgRepo;

tests/testsuite/new.rs

@@ -422,9 +422,6 @@ fn subpackage_no_git() {
     assert!(!paths::root()
         .join("foo/components/subcomponent/.git")
         .is_file());
-    assert!(!paths::root()
-        .join("foo/components/subcomponent/.gitignore")
-        .is_file());
 }
 
 #[cargo_test]