fix 0-leaf dtypes, branch printout formatting, and STLstreamers with …

…a 'This' member

uproot/interp/auto.py

@@ -132,7 +132,7 @@ def interpret(branch, classes=None, swapbytes=True):
             else:
                 return asjagged(out)
 
-        else:
+        elif len(branch.fLeaves) > 1:
             fromdtype = numpy.dtype([(leaf.fName.decode("ascii"), _leaf2dtype(leaf).newbyteorder(">")) for leaf in branch.fLeaves])
             if swapbytes:
                 todtype = numpy.dtype([(leaf.fName.decode("ascii"), _leaf2dtype(leaf).newbyteorder("=")) for leaf in branch.fLeaves])

uproot/tree.py

@@ -163,6 +163,9 @@ def _attachstreamer(self, branch, streamer, streamerinfosmap):
                     # FIXME: can only determine streamer by reading some values?
                     return
 
+            elif len(streamer.fElements) == 1 and isinstance(streamer.fElements[0], uproot.rootio.TStreamerSTL) and streamer.fElements[0].fName == b"This":
+                return self._attachstreamer(branch, streamer.fElements[0], streamerinfosmap)
+
         branch._streamer = streamer
 
         digDeeperTypes = (uproot.rootio.TStreamerObject, uproot.rootio.TStreamerObjectAny, uproot.rootio.TStreamerObjectPointer, uproot.rootio.TStreamerObjectAnyPointer)
@@ -379,8 +382,8 @@ def _format(self, indent=""):
             out.extend(branch._format(indent))
         return out
 
-    def format(self):
-        return "\n".join(self._format())
+    def format(self, foldnames=False):
+        return "\n".join(self._format(foldnames))
 
     def _normalize_branches(self, arg):
         if arg is None:                                    # no specification; read all branches
@@ -1223,25 +1226,25 @@ def _basketkey(self, source, i, complete):
             raise IndexError("index {0} out of range for branch with {1} baskets".format(i, self.numbaskets))
         return self._BasketKey(source.parent(), Cursor(self.fBasketSeek[i]), uproot.source.compressed.Compression(self.fCompress), complete)
 
-    def _format(self, indent="", strip=""):
+    def _format(self, foldnames, indent="", strip=""):
         name = self.fName.decode("ascii")
-        if name.startswith(strip + "."):
+        if foldnames and name.startswith(strip + "."):
             name = name[len(strip) + 1:]
 
-        if len(name) > 40:
-            out = [indent + name, indent + "{0:40s} {1:20s} {2}".format("", self._streamer.__class__.__name__, interpret(self))]
+        if len(name) > 26:
+            out = [indent + name, indent + "{0:26s} {1:26s} {2}".format("", self._streamer.__class__.__name__, interpret(self))]
         else:
-            out = [indent + "{0:40s} {1:20s} {2}".format(name, self._streamer.__class__.__name__, interpret(self))]
+            out = [indent + "{0:26s} {1:26s} {2}".format(name, self._streamer.__class__.__name__, interpret(self))]
 
         for branch in self.fBranches:
-            out.extend(branch._format("    ", self.fName))
+            out.extend(branch._format(foldnames, indent + "  " if foldnames else indent, self.fName))
         if len(self.fBranches) > 0 and out[-1] != "":
             out.append("")
 
         return out
 
-    def format(self):
-        return "\n".join(self._format())
+    def format(self, foldnames=False):
+        return "\n".join(self._format(foldnames))
 
     def __len__(self):
         return self.numentries

uproot/version.py

@@ -30,7 +30,7 @@
 
 import re
 
-__version__ = "2.1.4"
+__version__ = "2.1.5"
 version = __version__
 version_info = tuple(re.split(r"[-\.]", __version__))