diff --git a/Makefile b/Makefile
index d40aa6a7d8cef4dd36a16e88071faf37c16fb731..648469e625bebeea355ff8599499cdb16da99a2f 100644
--- a/Makefile
+++ b/Makefile
@@ -419,6 +419,7 @@ $(patsubst %.sh,%,$(SCRIPT_SH)) : % : %.sh
 	rm -f $@
 	sed -e '1s|#!.*/sh|#!$(call shq,$(SHELL_PATH))|' \
 	    -e 's/@@GIT_VERSION@@/$(GIT_VERSION)/g' \
+	    -e 's/@@NO_CURL@@/$(NO_CURL)/g' \
 	    $@.sh >$@
 	chmod +x $@
 
diff --git a/git-checkout.sh b/git-checkout.sh
index 6a87c717e9cb8f0358ceca85ec7df8cf44f625d5..463ed2eaff906edaeb0f6d3f8138798e373c6495 100755
--- a/git-checkout.sh
+++ b/git-checkout.sh
@@ -22,7 +22,7 @@ while [ "$#" != "0" ]; do
 		[ -e "$GIT_DIR/refs/heads/$newbranch" ] &&
 			die "git checkout: branch $newbranch already exists"
 		git-check-ref-format "heads/$newbranch" ||
-			die "we do not like '$newbranch' as a branch name."
+			die "git checkout: we do not like '$newbranch' as a branch name."
 		;;
 	"-f")
 		force=1
@@ -75,9 +75,15 @@ done
 
 if test "$#" -ge 1
 then
+	hint=
+	if test "$#" -eq 1
+	then
+		hint="
+Did you intend to checkout '$@' which can not be resolved as commit?"
+	fi
 	if test '' != "$newbranch$force$merge"
 	then
-		die "updating paths and switching branches or forcing are incompatible."
+		die "git checkout: updating paths is incompatible with switching branches/forcing$hint"
 	fi
 	if test '' != "$new"
 	then
@@ -117,7 +123,8 @@ fi
 
 [ -z "$branch$newbranch" ] &&
 	[ "$new" != "$old" ] &&
-	die "git checkout: you need to specify a new branch name"
+	die "git checkout: to checkout the requested commit you need to specify 
+              a name for a new branch which is created and switched to"
 
 if [ "$force" ]
 then
@@ -165,8 +172,10 @@ else
 	exit 0
     )
     saved_err=$?
-    test "$new" = "$old" ||
-	git diff-index --name-status "$new"
+    if test "$saved_err" = 0
+    then
+	test "$new" = "$old" || git diff-index --name-status "$new"
+    fi
     (exit $saved_err)
 fi
 
diff --git a/git-clone.sh b/git-clone.sh
index 47f3ec9761ba3e681e3035e6ae1c7449a6177a5e..e192b08c0dc3ab410e371fe07af96b9b5b59f22a 100755
--- a/git-clone.sh
+++ b/git-clone.sh
@@ -206,7 +206,13 @@ yes,yes)
 		fi
 		;;
 	http://*)
-		clone_dumb_http "$repo" "$D"
+		if test -z "@@NO_CURL@@"
+		then
+			clone_dumb_http "$repo" "$D"
+		else
+			echo >&2 "http transport not supported, rebuild Git with curl support"
+			exit 1
+		fi
 		;;
 	*)
 		cd "$D" && case "$upload_pack" in