Merge pull request #1461 from github/check-git-version

check the git version is ok in some key commands

commands/command_clone.go

@@ -19,6 +19,7 @@ var (
 )
 
 func cloneCommand(cmd *cobra.Command, args []string) {
+	requireGitVersion()
 
 	// We pass all args to git clone
 	err := git.CloneWithoutFilters(cloneFlags, args)

commands/command_install.go

@@ -1,9 +1,10 @@
 package commands
 
 import (
+	"os"
+
 	"github.com/github/git-lfs/lfs"
 	"github.com/spf13/cobra"
-	"os"
 )
 
 var (
@@ -14,6 +15,8 @@ var (
 )
 
 func installCommand(cmd *cobra.Command, args []string) {
+	requireGitVersion()
+
 	if localInstall {
 		requireInRepo()
 	}

commands/command_pre_push.go

@@ -43,6 +43,8 @@ func prePushCommand(cmd *cobra.Command, args []string) {
 		os.Exit(1)
 	}
 
+	requireGitVersion()
+
 	// Remote is first arg
 	if err := git.ValidateRemote(args[0]); err != nil {
 		Exit("Invalid remote name %q", args[0])

commands/command_pull.go

@@ -8,6 +8,7 @@ import (
 )
 
 func pullCommand(cmd *cobra.Command, args []string) {
+	requireGitVersion()
 	requireInRepo()
 
 	if len(args) > 0 {

commands/command_push.go

@@ -113,6 +113,8 @@ func pushCommand(cmd *cobra.Command, args []string) {
 		os.Exit(1)
 	}
 
+	requireGitVersion()
+
 	// Remote is first arg
 	if err := git.ValidateRemote(args[0]); err != nil {
 		Exit("Invalid remote name %q", args[0])

commands/command_track.go

@@ -26,6 +26,8 @@ var (
 )
 
 func trackCommand(cmd *cobra.Command, args []string) {
+	requireGitVersion()
+
 	if config.LocalGitDir == "" {
 		Print("Not a git repository.")
 		os.Exit(128)

commands/command_update.go

@@ -16,6 +16,7 @@ var (
 // updateCommand is used for updating parts of Git LFS that reside under
 // .git/lfs.
 func updateCommand(cmd *cobra.Command, args []string) {
+	requireGitVersion()
 	requireInRepo()
 
 	lfsAccessRE := regexp.MustCompile(`\Alfs\.(.*)\.access\z`)

commands/commands.go

@@ -118,23 +118,23 @@ func FullError(err error) {
 }
 
 func errorWith(err error, fatalErrFn func(error, string, ...interface{}), errFn func(string, ...interface{})) {
-		var innermsg string
-		if inner := errutil.GetInnerError(err); inner != nil {
-			innermsg = inner.Error()
-		}
-
-		errmsg := err.Error()
-		if errmsg != innermsg {
-			Error(innermsg)
-		}
-
-		if Debugging || errutil.IsFatalError(err) {
-			fatalErrFn(err, errmsg)
-		} else {
-			errFn(errmsg)
-		}
+	var innermsg string
+	if inner := errutil.GetInnerError(err); inner != nil {
+		innermsg = inner.Error()
 	}
 
+	errmsg := err.Error()
+	if errmsg != innermsg {
+		Error(innermsg)
+	}
+
+	if Debugging || errutil.IsFatalError(err) {
+		fatalErrFn(err, errmsg)
+	} else {
+		errFn(errmsg)
+	}
+}
+
 // Debug prints a formatted message if debugging is enabled.  The formatted
 // message also shows up in the panic log, if created.
 func Debug(format string, args ...interface{}) {
@@ -334,6 +334,18 @@ func isCommandEnabled(cfg *config.Configuration, cmd string) bool {
 	return cfg.Os.Bool(fmt.Sprintf("GITLFS%sENABLED", strings.ToUpper(cmd)), false)
 }
 
+func requireGitVersion() {
+	minimumGit := "1.8.2"
+
+	if !git.Config.IsGitVersionAtLeast(minimumGit) {
+		gitver, err := git.Config.Version()
+		if err != nil {
+			Exit("Error getting git version: %s", err)
+		}
+		Exit("git version >= %s is required for Git LFS, your version: %s", minimumGit, gitver)
+	}
+}
+
 func init() {
 	log.SetOutput(ErrorWriter)
 }

git/git.go

@@ -14,6 +14,7 @@ import (
 	"regexp"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/github/git-lfs/subprocess"
@@ -306,6 +307,8 @@ func UpdateIndex(file string) error {
 }
 
 type gitConfig struct {
+	gitVersion string
+	mu         sync.Mutex
 }
 
 var Config = &gitConfig{}
@@ -398,7 +401,18 @@ func (c *gitConfig) ListFromFile(f string) (string, error) {
 
 // Version returns the git version
 func (c *gitConfig) Version() (string, error) {
-	return subprocess.SimpleExec("git", "version")
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	if len(c.gitVersion) == 0 {
+		v, err := subprocess.SimpleExec("git", "version")
+		if err != nil {
+			return v, err
+		}
+		c.gitVersion = v
+	}
+
+	return c.gitVersion, nil
 }
 
 // IsVersionAtLeast returns whether the git version is the one specified or higher