Never download anything when using the checkout command

This was always the intention but the PointerSmudge functions would
automatically do it if the local files were missing. Now they take a
boolean argument to say whether to download or not, and the case of
skipped smudge is dealt with by writing out the original pointer data
and returning a known non-fatal error.

commands/command_checkout.go

@@ -182,9 +182,15 @@ func checkoutWithChan(in <-chan *lfs.WrappedPointer) {
 		// OK now we can (over)write the file content
 		repopathchan <- pointer.Name
 		cwdfilepath := <-cwdpathchan
-		err = lfs.PointerSmudgeToFile(cwdfilepath, pointer.Pointer, nil)
+		// smudge but set auto-download to false
+		err = lfs.PointerSmudgeToFile(cwdfilepath, pointer.Pointer, false, nil)
 		if err != nil {
-			Panic(err, "Could not checkout file")
+			if err == lfs.DownloadDeclinedError {
+				// acceptable error, data not local (fetch not run or include/exclude)
+				LoggedError(err, "Skipped checkout for %v, content not local. Use fetch to download.", pointer.Name)
+			} else {
+				Panic(err, "Could not checkout file")
+			}
 		}
 
 		updateIdxStdin.Write([]byte(cwdfilepath + "\n"))

commands/command_smudge.go

@@ -57,7 +57,7 @@ func smudgeCommand(cmd *cobra.Command, args []string) {
 		Error(err.Error())
 	}
 
-	err = ptr.Smudge(os.Stdout, filename, cb)
+	err = ptr.Smudge(os.Stdout, filename, true, cb)
 	if file != nil {
 		file.Close()
 	}

lfs/pointer.go

@@ -59,8 +59,8 @@ func NewPointerExtension(name string, priority int, oid string) *PointerExtensio
 	return &PointerExtension{name, priority, oid, oidType}
 }
 
-func (p *Pointer) Smudge(writer io.Writer, workingfile string, cb CopyCallback) error {
-	return PointerSmudge(writer, p, workingfile, cb)
+func (p *Pointer) Smudge(writer io.Writer, workingfile string, download bool, cb CopyCallback) error {
+	return PointerSmudge(writer, p, workingfile, download, cb)
 }
 
 func (p *Pointer) Encode(writer io.Writer) (int, error) {

lfs/pointer_smudge.go

@@ -1,6 +1,7 @@
 package lfs
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -11,19 +12,30 @@ import (
 	contentaddressable "github.com/github/git-lfs/vendor/_nuts/github.com/technoweenie/go-contentaddressable"
 )
 
-func PointerSmudgeToFile(filename string, ptr *Pointer, cb CopyCallback) error {
+var (
+	DownloadDeclinedError = errors.New("File missing and download is not allowed")
+)
+
+func PointerSmudgeToFile(filename string, ptr *Pointer, download bool, cb CopyCallback) error {
 	os.MkdirAll(filepath.Dir(filename), 0755)
 	file, err := os.Create(filename)
 	if err != nil {
 		return fmt.Errorf("Could not create working directory file: %v", err)
 	}
 	defer file.Close()
-	if err := PointerSmudge(file, ptr, filename, cb); err != nil {
-		return fmt.Errorf("Could not write working directory file: %v", err)
+	if err := PointerSmudge(file, ptr, filename, download, cb); err != nil {
+		if err == DownloadDeclinedError {
+			// write placeholder data instead
+			file.Seek(0, os.SEEK_SET)
+			ptr.Encode(file)
+			return err
+		} else {
+			return fmt.Errorf("Could not write working directory file: %v", err)
+		}
 	}
 	return nil
 }
-func PointerSmudge(writer io.Writer, ptr *Pointer, workingfile string, cb CopyCallback) error {
+func PointerSmudge(writer io.Writer, ptr *Pointer, workingfile string, download bool, cb CopyCallback) error {
 	mediafile, err := LocalMediaPath(ptr.Oid)
 	if err != nil {
 		return err
@@ -41,7 +53,11 @@ func PointerSmudge(writer io.Writer, ptr *Pointer, workingfile string, cb CopyCa
 
 	var wErr *WrappedError
 	if statErr != nil || stat == nil {
-		wErr = downloadFile(writer, ptr, workingfile, mediafile, cb)
+		if download {
+			wErr = downloadFile(writer, ptr, workingfile, mediafile, cb)
+		} else {
+			return DownloadDeclinedError
+		}
 	} else {
 		wErr = readLocalFile(writer, ptr, mediafile, workingfile, cb)
 	}

test/test-checkout.sh

@@ -15,6 +15,7 @@ begin_test "checkout"
   grep "Tracking \*.dat" track.log
 
   contents="something something"
+  contentsize=19
   contents_oid=$(printf "$contents" | shasum -a 256 | cut -f 1 -d " ")
 
   # Same content everywhere is ok, just one object in lfs db
@@ -34,7 +35,7 @@ begin_test "checkout"
   [ "$contents" = "$(cat folder1/nested.dat)" ]
   [ "$contents" = "$(cat folder2/nested.dat)" ]
 
-  assert_pointer "master" "file1.dat" "$contents_oid" 19
+  assert_pointer "master" "file1.dat" "$contents_oid" $contentsize
 
   # Remove the working directory
   rm -rf file1.dat file2.dat file3.dat folder1/nested.dat folder2/nested.dat
@@ -89,5 +90,16 @@ begin_test "checkout"
   [ "$contents" = "$(cat folder1/nested.dat)" ]
   [ "$contents" = "$(cat folder2/nested.dat)" ]
 
+  # test checkout with missing data doesn't fail
+  git push origin master
+  rm -rf .git/lfs/objects
+  rm file*.dat
+  git lfs checkout
+  [ "$(pointer $contents_oid $contentsize)" = "$(cat file1.dat)" ]
+  [ "$(pointer $contents_oid $contentsize)" = "$(cat file2.dat)" ]
+  [ "$(pointer $contents_oid $contentsize)" = "$(cat file3.dat)" ]
+  [ "$contents" = "$(cat folder1/nested.dat)" ]
+  [ "$contents" = "$(cat folder2/nested.dat)" ]
+
 )
 end_test