* builtins.filterSource: pass the type of the file ("regular",

  "directory", "symlink") as the second argument to the filter
  predicate.

3 files changed, 23 insertions, 2 deletions

diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index bc6e290a48fc..270bc4446bff 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -7,6 +7,10 @@
 #include "expr-to-xml.hh"
 #include "nixexpr-ast.hh"
 
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
 #include <algorithm>
 
 
@@ -739,7 +743,20 @@ struct FilterFromExpr : PathFilter
 
     bool operator () (const Path & path)
     {
-        Expr call = makeCall(filter, makePath(toATerm(path)));
+        struct stat st;
+        if (lstat(path.c_str(), &st))
+            throw SysError(format("getting attributes of path `%1%'") % path);
+
+        Expr call =
+            makeCall(
+                makeCall(filter, makePath(toATerm(path))),
+                makeStr(
+                    S_ISREG(st.st_mode) ? "regular" :
+                    S_ISDIR(st.st_mode) ? "directory" :
+                    S_ISLNK(st.st_mode) ? "symlink" :
+                    "unknown" /* not supported, will fail! */
+                    ));
+                
         return evalBool(state, call);
     }
 };
diff --git a/tests/filter-source.nix.in b/tests/filter-source.nix.in
index 2b5c23d31765..8493835c2b93 100644
--- a/tests/filter-source.nix.in
+++ b/tests/filter-source.nix.in
@@ -3,5 +3,7 @@ derivation {
   system = "@system@";
   builder = "@shell@";
   args = ["-e" "-x" (builtins.toFile "builder" "PATH=@testPath@; ln -s $input $out")];
-  input = builtins.filterSource (path: baseNameOf (toString path) != "foo") ./test-tmp/filterin;
+  input =
+    let filter = path: type: type != "symlink" && baseNameOf (toString path) != "foo";
+    in builtins.filterSource filter ./test-tmp/filterin;
 }
diff --git a/tests/filter-source.sh b/tests/filter-source.sh
index 4880969ba7ad..96ccaedca028 100644
--- a/tests/filter-source.sh
+++ b/tests/filter-source.sh
@@ -5,9 +5,11 @@ mkdir $TEST_ROOT/filterin
 mkdir $TEST_ROOT/filterin/foo
 touch $TEST_ROOT/filterin/foo/bar
 touch $TEST_ROOT/filterin/xyzzy
+ln -s xyzzy $TEST_ROOT/filterin/link
 
 $NIX_BIN_DIR/nix-build ./filter-source.nix -o $TEST_ROOT/filterout
 
 set -x
 test ! -e $TEST_ROOT/filterout/foo/bar
 test -e $TEST_ROOT/filterout/xyzzy
+test ! -L $TEST_ROOT/filterout/link