s/renameElseCopy/renameWithFallback/

Changes both name and implementation of renameElseCopy to reflect that
the outcome will be like a rename, even in the event of a cross-device
link error.

ensure.go

@@ -338,9 +338,10 @@ func deduceConstraint(s string) gps.Constraint {
 	return gps.NewVersion(s)
 }
 
-// renameElseCopy attempts to rename a file or directory, but falls back to
-// copying in the event of a cross-link device error.
-func renameElseCopy(src, dest string) error {
+// renameWithFallback attempts to rename a file or directory, but falls back to
+// copying in the event of a cross-link device error. If the fallback copy
+// succeeds, src is still removed, emulating normal rename behavior.
+func renameWithFallback(src, dest string) error {
 	fi, err := os.Lstat(src)
 	if err != nil {
 		return err
@@ -360,12 +361,13 @@ func renameElseCopy(src, dest string) error {
 	// copy if we detect that case. syscall.EXDEV is the common name for the
 	// cross device link error which has varying output text across different
 	// operating systems.
+	var cerr error
 	if terr.Err == syscall.EXDEV {
 		vlogf("Cross link err (is temp dir on same partition as project?); falling back to manual copy: %s", terr)
 		if fi.IsDir() {
-			return copyFolder(src, dest)
+			cerr = copyFolder(src, dest)
 		} else {
-			return copyFile(src, dest)
+			cerr = copyFile(src, dest)
 		}
 	} else if runtime.GOOS == "windows" {
 		// In windows it can drop down to an operating system call that
@@ -377,14 +379,20 @@ func renameElseCopy(src, dest string) error {
 		if ok && noerr == 0x11 {
 			vlogf("Cross link err (is temp dir on same partition as project?); falling back to manual copy: %s", terr)
 			if fi.IsDir() {
-				return copyFolder(src, dest)
+				cerr = copyFolder(src, dest)
 			} else {
-				return copyFile(src, dest)
+				cerr = copyFile(src, dest)
 			}
 		}
+	} else {
+		return terr
 	}
 
-	return terr
+	if cerr != nil {
+		return cerr
+	}
+
+	return os.RemoveAll(src)
 }
 
 // copyFolder takes in a directory and copies its contents to the destination.

txn_writer.go

@@ -154,7 +154,7 @@ func (sw safeWriter) writeAllSafe(forceVendor bool) error {
 		if _, err := os.Stat(mpath); err == nil {
 			// move out the old one
 			tmploc := filepath.Join(td, manifestName+".orig")
-			failerr = renameElseCopy(mpath, tmploc)
+			failerr = renameWithFallback(mpath, tmploc)
 			if failerr != nil {
 				goto fail
 			}
@@ -162,7 +162,7 @@ func (sw safeWriter) writeAllSafe(forceVendor bool) error {
 		}
 
 		// move in the new one
-		failerr = renameElseCopy(filepath.Join(td, manifestName), mpath)
+		failerr = renameWithFallback(filepath.Join(td, manifestName), mpath)
 		if failerr != nil {
 			goto fail
 		}
@@ -173,7 +173,7 @@ func (sw safeWriter) writeAllSafe(forceVendor bool) error {
 			// move out the old one
 			tmploc := filepath.Join(td, lockName+".orig")
 
-			failerr = renameElseCopy(lpath, tmploc)
+			failerr = renameWithFallback(lpath, tmploc)
 			if failerr != nil {
 				goto fail
 			}
@@ -181,7 +181,7 @@ func (sw safeWriter) writeAllSafe(forceVendor bool) error {
 		}
 
 		// move in the new one
-		failerr = renameElseCopy(filepath.Join(td, lockName), lpath)
+		failerr = renameWithFallback(filepath.Join(td, lockName), lpath)
 		if failerr != nil {
 			goto fail
 		}
@@ -199,7 +199,7 @@ func (sw safeWriter) writeAllSafe(forceVendor bool) error {
 				vendorbak = filepath.Join(td, "vendor.orig")
 			}
 
-			failerr = renameElseCopy(vpath, vendorbak)
+			failerr = renameWithFallback(vpath, vendorbak)
 			if failerr != nil {
 				goto fail
 			}
@@ -207,7 +207,7 @@ func (sw safeWriter) writeAllSafe(forceVendor bool) error {
 		}
 
 		// move in the new one
-		failerr = renameElseCopy(filepath.Join(td, "vendor"), vpath)
+		failerr = renameWithFallback(filepath.Join(td, "vendor"), vpath)
 		if failerr != nil {
 			goto fail
 		}
@@ -227,7 +227,7 @@ fail:
 	// If we failed at any point, move all the things back into place, then bail
 	for _, pair := range restore {
 		// Nothing we can do on err here, as we're already in recovery mode
-		renameElseCopy(pair.from, pair.to)
+		renameWithFallback(pair.from, pair.to)
 	}
 	return failerr
 }