crystal-lang · Jan 20, 2017 · Jan 20, 2017 · Jan 20, 2017
Showing with 36 additions and 2 deletions.

+21 −0 spec/compiler/semantic/exception_spec.cr

+2 −2 spec/spec_helper.cr

+4 −0 src/compiler/crystal/semantic/ast.cr

+9 −0 src/compiler/crystal/semantic/main_visitor.cr
diff --git a/spec/compiler/semantic/exception_spec.cr b/spec/compiler/semantic/exception_spec.cr
@@ -421,4 +421,25 @@ describe "Semantic: exception" do
       ),
       "instance variable '@x' of Foo must be Int32, not Nil"
   end
+
+  it "assigns var inside ensure (1) (#3919)" do
+    assert_type(%(
+      begin
+      ensure
+        a = 1
+      end
+      a
+      )) { int32 }
+  end
+
+  it "assigns var inside ensure (2) (#3919)" do
+    assert_type(%(
+      a = true
+      begin
+      ensure
+        a = 1
+      end
+      a
+      )) { int32 }
+  end
 end
diff --git a/spec/spec_helper.cr b/spec/spec_helper.cr
@@ -215,8 +215,8 @@ def assert_after_cleanup(before, after)
   result.node.to_s.strip.should eq(after.strip)
 end
 
-def assert_syntax_error(str, message = nil, line = nil, column = nil, metafile = __FILE__, metaline = __LINE__)
-  it "says syntax error on #{str.inspect}", metafile, metaline do
+def assert_syntax_error(str, message = nil, line = nil, column = nil, metafile = __FILE__, metaline = __LINE__, metaendline = __END_LINE__)
+  it "says syntax error on #{str.inspect}", metafile, metaline, metaendline do
     begin
       parse str
       fail "expected SyntaxException to be raised", metafile, metaline

diff --git a/src/compiler/crystal/semantic/ast.cr b/src/compiler/crystal/semantic/ast.cr
@@ -453,6 +453,10 @@ module Crystal
       io << " (assigned-to)" if assigned_to?
       io << " (object id: #{object_id})"
     end
+
+    def pretty_print(pp)
+      pp.text inspect
+    end
   end
 
   alias MetaVars = Hash(String, MetaVar)

diff --git a/src/compiler/crystal/semantic/main_visitor.cr b/src/compiler/crystal/semantic/main_visitor.cr
@@ -2548,9 +2548,18 @@ module Crystal
             end
           end
 
+          before_ensure_vars = @vars.dup
+
           node_ensure.accept self
 
           @vars = after_handler_vars
+
+          # Variables declared or overwritten inside the ensure block
+          # must remain after the exception handler
+          exception_handler_vars.each do |name, var|
+            before_var = before_ensure_vars[name]?
+            @vars[name] = var unless var.same?(before_var)
+          end
         else
           @vars = exception_handler_vars
         end