fix(R-1187 a,b,d,f,g): .fab — links carried and restored safely, FIFOs refused, owners kept, busy and bad-path refusals, postgis + ON_ERROR_STOP

Red-proved (6 tests). Commit only.

controller/internal/appexport/fabplan.go

@@ -2,6 +2,7 @@ package appexport
 
 import (
 	"archive/tar"
+	"gitea.dooplex.hu/admin/felhom-controller/internal/util"
 	"io"
 	"os"
 	"path/filepath"
@@ -289,7 +290,20 @@ func tarDirectoryExcluding(sourceDir, outputPath string, excludeRels []string) e
 				return nil
 			}
 		}
-		header, err := tar.FileInfoHeader(info, "")
+		// R-1187 (a): a symlink is carried AS A LINK (its target's bytes never — the walk used to copy them into the link
+		// header, the tar failed, and the whole folder was left out); a FIFO, socket or device stops the export with a
+		// sentence naming the path (os.Open on a FIFO used to HANG the export). Pinned by TestR1187a_*.
+		mode := info.Mode()
+		if mode&(os.ModeNamedPipe|os.ModeSocket|os.ModeDevice|os.ModeCharDevice|os.ModeIrregular) != 0 {
+			return util.MsgError("err.appexport.kulonleges_fajl", path)
+		}
+		link := ""
+		if mode&os.ModeSymlink != 0 {
+			if link, err = os.Readlink(path); err != nil {
+				return err
+			}
+		}
+		header, err := tar.FileInfoHeader(info, link)
 		if err != nil {
 			return err
 		}
@@ -297,7 +311,7 @@ func tarDirectoryExcluding(sourceDir, outputPath string, excludeRels []string) e
 		if err := tw.WriteHeader(header); err != nil {
 			return err
 		}
-		if info.IsDir() {
+		if info.IsDir() || link != "" {
 			return nil
 		}
 		f, err := os.Open(path)