implement force pull

go/cmd/dolt/cli/arg_parser_helpers.go

@@ -217,7 +217,7 @@ func CreatePullArgParser() *argparser.ArgParser {
 	ap.ArgListHelp = append(ap.ArgListHelp, [2]string{"remoteBranch", "The name of a branch on the specified remote to be merged into the current working set."})
 	ap.SupportsFlag(SquashParam, "", "Merge changes to the working set without updating the commit history")
 	ap.SupportsFlag(NoFFParam, "", "Create a merge commit even when the merge resolves as a fast-forward.")
-	ap.SupportsFlag(ForceFlag, "f", "Ignore any foreign key warnings and proceed with the commit.")
+	ap.SupportsFlag(ForceFlag, "f", "Update from the remote HEAD even if there are errors or the local branch has diverged.")
 	ap.SupportsFlag(CommitFlag, "", "Perform the merge and commit the result. This is the default option, but can be overridden with the --no-commit flag. Note that this option does not affect fast-forward merges, which don't create a new merge commit, and if any merge conflicts or constraint violations are detected, no commit will be attempted.")
 	ap.SupportsFlag(NoCommitFlag, "", "Perform the merge and stop just before creating a merge commit. Note this will not prevent a fast-forward merge; use the --no-ff arg together with the --no-commit arg to prevent both fast-forwards and merge commits.")
 	ap.SupportsFlag(NoEditFlag, "", "Use an auto-generated commit message when creating a merge commit. The default for interactive CLI sessions is to open an editor.")

go/cmd/dolt/commands/pull.go

@@ -16,6 +16,7 @@ package commands
 
 import (
 	"context"
+	"errors"
 	"fmt"
 
 	"github.com/dolthub/go-mysql-server/sql"
@@ -160,7 +161,16 @@ func pullHelper(ctx context.Context, sqlCtx *sql.Context, queryist cli.Queryist,
 			}
 
 			err = dEnv.DoltDB.FastForward(ctx, remoteTrackRef, srcDBCommit)
-			if err != nil {
+			if errors.Is(err, datas.ErrMergeNeeded) && pullSpec.Force {
+				h, err := srcDBCommit.HashOf()
+				if err != nil {
+					return err
+				}
+				err = dEnv.DoltDB.SetHead(ctx, branchRef, h)
+				if err != nil {
+					return err
+				}
+			} else if err != nil {
 				return fmt.Errorf("fetch failed; %w", err)
 			}
 
@@ -178,7 +188,7 @@ func pullHelper(ctx context.Context, sqlCtx *sql.Context, queryist cli.Queryist,
 
 			name, email, configErr := env.GetNameAndEmail(dEnv.Config)
 			// If the name and email aren't set we can set them to empty values for now. This is only valid for ff
-			// merges which detect for later.
+			// merges which we detect later.
 			if configErr != nil {
 				if pullSpec.Noff {
 					return configErr

go/libraries/doltcore/env/remotes.go

@@ -406,7 +406,12 @@ type PullSpec struct {
 // NewPullSpec returns PullSpec object using arguments passed into this function, which are remoteName, remoteRefName,
 // squash, noff, noCommit, noEdit,  refSpecs, force and remoteOnly. This function validates remote and gets remoteRef
 // for given remoteRefName; if it's not defined, it uses current branch to get its upstream branch if it exists.
-func NewPullSpec(_ context.Context, rsr RepoStateReader, remoteName, remoteRefName string, squash, noff, noCommit, noEdit, force, remoteOnly bool) (*PullSpec, error) {
+func NewPullSpec(
+		_ context.Context,
+		rsr RepoStateReader,
+		remoteName, remoteRefName string,
+		squash, noff, noCommit, noEdit, force, remoteOnly bool,
+) (*PullSpec, error) {
 	refSpecs, err := GetRefSpecs(rsr, remoteName)
 	if err != nil {
 		return nil, err

go/libraries/doltcore/sqle/dprocedures/dolt_pull.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"sync"
 
+	"github.com/dolthub/dolt/go/store/datas"
 	"github.com/dolthub/go-mysql-server/sql"
 
 	"github.com/dolthub/dolt/go/cmd/dolt/cli"
@@ -129,7 +130,16 @@ func doDoltPull(ctx *sql.Context, args []string) (int, int, error) {
 
 			// TODO: this could be replaced with a canFF check to test for error
 			err = dbData.Ddb.FastForward(ctx, remoteTrackRef, srcDBCommit)
-			if err != nil {
+			if errors.Is(err, datas.ErrMergeNeeded) && pullSpec.Force {
+				h, err := srcDBCommit.HashOf()
+				if err != nil {
+					return noConflictsOrViolations, threeWayMerge, err
+				}
+				err = dbData.Ddb.SetHead(ctx, branchRef, h)
+				if err != nil {
+					return noConflictsOrViolations, threeWayMerge, err
+				}
+			} else if err != nil {
 				return noConflictsOrViolations, threeWayMerge, fmt.Errorf("fetch failed; %w", err)
 			}