Make --showlocals work together with --tb=short

Enable showing local variables when asked to do so in the short
traceback mode.

Fixes #494

AUTHORS

@@ -208,6 +208,7 @@ Omer Hadari
 Ondřej Súkup
 Oscar Benjamin
 Patrick Hayes
+Pauli Virtanen
 Paweł Adamczak
 Pedro Algarvio
 Philipp Loose

changelog/6384.improvement.rst

@@ -0,0 +1 @@
+Make `--showlocals` work also with `--tb=short`.

src/_pytest/_code/code.py

@@ -785,8 +785,6 @@ class FormattedExcinfo:
                 message = excinfo and excinfo.typename or ""
             path = self._makepath(entry.path)
             filelocrepr = ReprFileLocation(path, entry.lineno + 1, message)
-            localsrepr = None
-            if not short:
             localsrepr = self.repr_locals(entry.locals)
             return ReprEntry(lines, reprargs, localsrepr, filelocrepr, style)
         if excinfo:
@@ -1044,6 +1042,8 @@ class ReprEntry(TerminalRepr):
             for line in self.lines:
                 red = line.startswith("E   ")
                 tw.line(line, bold=True, red=red)
+            if self.reprlocals:
+                self.reprlocals.toterminal(tw, indent=" " * 8)
             return
         if self.reprfuncargs:
             self.reprfuncargs.toterminal(tw)
@@ -1085,9 +1085,9 @@ class ReprLocals(TerminalRepr):
     def __init__(self, lines: Sequence[str]) -> None:
         self.lines = lines
 
-    def toterminal(self, tw) -> None:
+    def toterminal(self, tw, indent="") -> None:
         for line in self.lines:
-            tw.line(line)
+            tw.line(indent + line)
 
 
 class ReprFuncArgs(TerminalRepr):

testing/test_terminal.py

@@ -670,6 +670,26 @@ class TestTerminalFunctional:
             ]
         )
 
+    def test_showlocals_short(self, testdir):
+        p1 = testdir.makepyfile(
+            """
+            def test_showlocals_short():
+                x = 3
+                y = "xxxx"
+                assert 0
+        """
+        )
+        result = testdir.runpytest(p1, "-l", "--tb=short")
+        result.stdout.fnmatch_lines(
+            [
+                "test_showlocals_short.py:*",
+                "    assert 0",
+                "E   assert 0",
+                "        x          = 3",
+                "        y          = 'xxxx'",
+            ]
+        )
+
     @pytest.fixture
     def verbose_testfile(self, testdir):
         return testdir.makepyfile(