Fix a problem when using --cache-show.

2 files changed, 34 insertions, 7 deletions

diff --git a/src/engine/SCons/Node/FS.py b/src/engine/SCons/Node/FS.py
index a17cee0..12b8869 100644
--- a/src/engine/SCons/Node/FS.py
+++ b/src/engine/SCons/Node/FS.py
@@ -1246,11 +1246,12 @@ class File(Entry):
             if self.fs.cache_show:
                 if CacheRetrieveSilent(self, None, None) == 0:
                     def do_print(action, targets, sources, env, self=self):
-                        al = action.strfunction(targets, self.sources, env)
-                        if not SCons.Util.is_List(al):
-                            al = [al]
-                        for a in al:
-                            action.show(a)
+                        if action.strfunction:
+                            al = action.strfunction(targets, self.sources, env)
+                            if not SCons.Util.is_List(al):
+                                al = [al]
+                            for a in al:
+                                action.show(a)
                     self._for_each_action(do_print)
                     return
             elif CacheRetrieve(self, None, None) == 0:
diff --git a/src/engine/SCons/Node/FSTests.py b/src/engine/SCons/Node/FSTests.py
index 13f171e..a80c8f9 100644
--- a/src/engine/SCons/Node/FSTests.py
+++ b/src/engine/SCons/Node/FSTests.py
@@ -86,11 +86,11 @@ class Action:
         return [self]
 
 class Builder:
-    def __init__(self, factory):
+    def __init__(self, factory, action=Action()):
         self.factory = factory
         self.env = Environment()
         self.overrides = {}
-        self.action = Action()
+        self.action = action
 
     def get_actions(self):
         return [self]
@@ -1499,6 +1499,32 @@ class CacheDirTestCase(unittest.TestCase):
             SCons.Warnings.warningAsException(old_warn_exceptions)
             SCons.Warnings.suppressWarningClass(SCons.Warnings.CacheWriteErrorWarning)
 
+        # Verify that we don't blow up if there's no strfunction()
+        # for an action.
+        act = Action()
+        act.strfunction = None
+        f8 = fs.File("cd.f8")
+        f8.builder_set(Builder(fs.File, action=act))
+        f8.env_set(Environment())
+        try:
+            SCons.Node.FS.CacheRetrieveSilent = retrieve_succeed
+            self.retrieved = []
+            built_it = None
+
+            f8.build()
+            assert self.retrieved == [f8], self.retrieved
+            assert built_it is None, built_it
+
+            SCons.Node.FS.CacheRetrieveSilent = retrieve_fail
+            self.retrieved = []
+            built_it = None
+
+            f8.build()
+            assert self.retrieved == [f8], self.retrieved
+            assert built_it, built_it
+        finally:
+            SCons.Node.FS.CacheRetrieveSilent = save_CacheRetrieveSilent
+
 class clearTestCase(unittest.TestCase):
     def runTest(self):
         fs = SCons.Node.FS.FS()