fix: force in git_branch_create()

Author: maelle

NEWS.md

@@ -1,5 +1,6 @@
 # gert (development version)
 
+- `git_branch_create()`: `force` now also applies to the checkout step, allowing branch creation even when local changes would be overwritten (@MichaelChirico, #177).
 - Improve manual pages (@olivroy, #227)
 - Fix badge links in `README.md` (@dpprdan, #189)
 - Use `NEWS.md` instead of `NEWS` (@olivroy, #209)

src/branch.c

@@ -49,7 +49,7 @@ SEXP R_git_create_branch(SEXP ptr, SEXP name, SEXP ref, SEXP checkout, SEXP forc
   git_reference *branch = NULL;
   const char *source = CHAR(STRING_ELT(ref, 0));
   git_checkout_options opts = GIT_CHECKOUT_OPTIONS_INIT;
-  opts.checkout_strategy = GIT_CHECKOUT_SAFE;
+  opts.checkout_strategy = Rf_asLogical(force) ? GIT_CHECKOUT_FORCE : GIT_CHECKOUT_SAFE;
   set_checkout_notify_cb(&opts);
   git_repository *repo = get_git_repository(ptr);
   git_object *revision = resolve_refish(ref, repo);

tests/testthat/test-branch.R

@@ -0,0 +1,28 @@
+test_that("git_branch_create force applies to checkout", {
+  repo <- git_init(tempfile("gert-tests-branch-force"))
+  on.exit(unlink(repo, recursive = TRUE))
+  configure_local_user(repo)
+
+  # First commit: hello.txt = "v1"
+  writeLines("v1", file.path(repo, "hello.txt"))
+  git_add("hello.txt", repo = repo)
+  first <- git_commit("First commit", repo = repo)
+
+  # Second commit: hello.txt = "v2"
+  writeLines("v2", file.path(repo, "hello.txt"))
+  git_add("hello.txt", repo = repo)
+  git_commit("Second commit", repo = repo)
+
+  # Unstaged local change: hello.txt = "v3"
+  writeLines("v3", file.path(repo, "hello.txt"))
+
+  # force = FALSE: checkout to first commit conflicts with local change
+  expect_error(
+    git_branch_create("oldbranch", ref = first, checkout = TRUE, force = FALSE, repo = repo)
+  )
+
+  # force = TRUE: checkout succeeds, overwriting local change
+  git_branch_create("oldbranch2", ref = first, checkout = TRUE, force = TRUE, repo = repo)
+  expect_equal(git_branch(repo = repo), "oldbranch2")
+  expect_equal(readLines(file.path(repo, "hello.txt")), "v1")
+})