Do not overwrite unchanged target

[goredo.git] / dep.go

diff --git a/dep.go b/dep.go
index 7c4e35aa700a4edf7c52dcb88b19e344321d3b90..0e4f24fb0a1ef8872145d2715271f8eb5cff8adc 100644 (file)
--- a/dep.go
+++ b/dep.go
@@ -86,7 +86,7 @@ func fileHash(fd *os.File) (string, error) {
        return hex.EncodeToString(h.Sum(nil)), nil
 }
 
-func depWrite(fdDep *os.File, cwd, tgt string) error {
+func depWrite(fdDep *os.File, cwd, tgt, hsh string) error {
        tracef(CDebug, "ifchange: %s <- %s", fdDep.Name(), tgt)
        fd, err := os.Open(path.Join(cwd, tgt))
        if err != nil {
@@ -104,9 +104,11 @@ func depWrite(fdDep *os.File, cwd, tgt string) error {
        if err != nil {
                return err
        }
-       hsh, err := fileHash(fd)
-       if err != nil {
-               return err
+       if hsh == "" {
+               hsh, err = fileHash(fd)
+               if err != nil {
+                       return err
+               }
        }
        fields := []recfile.Field{
                {Name: "Type", Value: DepTypeIfchange},
@@ -137,7 +139,7 @@ func depsWrite(fdDep *os.File, tgts []string) error {
                        panic(err)
                }
                if _, errStat := os.Stat(tgt); errStat == nil {
-                       err = depWrite(fdDep, tgtDir, tgtRel)
+                       err = depWrite(fdDep, tgtDir, tgtRel, "")
                } else {
                        tracef(CDebug, "ifchange: %s <- %s (non-existing)", fdDep.Name(), tgtRel)
                        fields := []recfile.Field{