Replace Neovim providers atomically and preserve dotfile links

test/shell.d/neovim-remote-yanks-test.sh

@@ -58,3 +58,54 @@ mv "$test_home/package.lua" "$test_home/package.saved"
 if run_migration; then fail "missing package source leaves migration pending"; fi
 cmp "$provider" "$SHELL_TEST_DIR/fixtures/neovim-clipboard/june.lua" || fail "missing source leaves provider unchanged"
 pass "old or missing package cannot mark an unrepaired provider complete"
+
+mv "$test_home/package.saved" "$test_home/package.lua"
+# A write that fails after producing partial output must never damage the live
+# provider. Exercise the real install destination with a failing replacement.
+cat >"$test_home/bin/install" <<'STUB'
+#!/bin/bash
+printf '%s' '-- truncated replacement' >"${@: -1}"
+exit 1
+STUB
+chmod +x "$test_home/bin/install"
+if run_migration; then fail "failed staging write leaves migration pending"; fi
+cmp "$provider" "$SHELL_TEST_DIR/fixtures/neovim-clipboard/june.lua" || fail "failed write preserves live provider"
+if compgen -G "$provider.new.*" >/dev/null; then fail "failed staging file is cleaned up"; fi
+rm "$test_home/bin/install"
+run_migration
+cmp "$provider" "$test_home/package.lua" || fail "retry repairs the recognized original"
+pass "failed write preserves original and retry succeeds"
+
+# Also fail the final rename, after successful staging.
+cp "$SHELL_TEST_DIR/fixtures/neovim-clipboard/july.lua" "$provider"
+printf '#!/bin/bash\nexit 1\n' >"$test_home/bin/mv"
+chmod +x "$test_home/bin/mv"
+if run_migration; then fail "failed rename leaves migration pending"; fi
+cmp "$provider" "$SHELL_TEST_DIR/fixtures/neovim-clipboard/july.lua" || fail "failed rename preserves original"
+if compgen -G "$provider.new.*" >/dev/null; then fail "failed rename staging file is cleaned up"; fi
+rm "$test_home/bin/mv"
+run_migration
+cmp "$provider" "$test_home/package.lua" || fail "retry after rename failure succeeds"
+pass "failed rename preserves original and retry succeeds"
+
+cp "$SHELL_TEST_DIR/fixtures/neovim-clipboard/july.lua" "$test_home/dotfile.lua"
+rm "$provider"
+ln -s "$test_home/dotfile.lua" "$provider"
+run_migration >"$test_home/output"
+[[ -L $provider ]] || fail "provider symlink is preserved"
+cmp "$test_home/dotfile.lua" "$SHELL_TEST_DIR/fixtures/neovim-clipboard/july.lua" || fail "symlink target is preserved"
+grep -q 'symlink-managed' "$test_home/output" || fail "linked provider receives guidance"
+rm "$provider"
+ln -s "$test_home/absent.lua" "$provider"
+run_migration
+[[ -L $provider && ! -e $provider ]] || fail "dangling symlink is preserved"
+rm "$provider"
+
+mkdir "$test_home/dotfiles"
+mv "$test_home/.config/nvim/lua/config" "$test_home/dotfiles/config"
+ln -s "$test_home/dotfiles/config" "$test_home/.config/nvim/lua/config"
+cp "$SHELL_TEST_DIR/fixtures/neovim-clipboard/july.lua" "$provider"
+run_migration
+[[ -L $test_home/.config/nvim/lua/config ]] || fail "linked config directory is preserved"
+cmp "$provider" "$SHELL_TEST_DIR/fixtures/neovim-clipboard/july.lua" || fail "provider in linked directory is preserved"
+pass "linked files, dangling links and linked directories are preserved"