Fixed pragmas on their own line after a backlash being ignored

Closes #199

ChangeLog

@@ -107,6 +107,10 @@ Release date: TBA
 
   Close #2877
 
+* Fixed a pragma comment on its own physical line being ignored when part
+  of a logical line with the previous physical line.
+
+  Close #199
 
 What's New in Pylint 2.3.0?
 ===========================

pylint/lint.py

@@ -832,7 +832,18 @@ def process_tokens(self, tokens):
         level options
         """
         control_pragmas = {"disable", "enable"}
+        prev_line = None
+        saw_newline = True
+        seen_newline = True
         for (tok_type, content, start, _, _) in tokens:
+            if prev_line and prev_line != start[0]:
+                saw_newline = seen_newline
+                seen_newline = False
+
+            prev_line = start[0]
+            if tok_type in (tokenize.NL, tokenize.NEWLINE):
+                seen_newline = True
+
             if tok_type != tokenize.COMMENT:
                 continue
             match = OPTION_RGX.search(content)
@@ -887,6 +898,10 @@ def process_tokens(self, tokens):
                             self.add_message("file-ignored", line=start[0])
                             self._ignore_file = True
                             return
+                        # If we did not see a newline between the previous line and now,
+                        # we saw a backslash so treat the two lines as one.
+                        if not saw_newline:
+                            meth(msgid, "module", start[0] - 1)
                         meth(msgid, "module", start[0])
                     except exceptions.UnknownMessageError:
                         self.add_message("bad-option-value", args=msgid, line=start[0])

pylint/test/functional/pragma_after_backslash.py

@@ -0,0 +1,10 @@
+"""Test that a pragma has an effect when separated by a backslash."""
+# pylint: disable=too-few-public-methods
+
+class Foo:
+    """block-disable test"""
+
+    def meth3(self):
+        """test one line disabling"""
+        print(self.bla) \
+           # pylint: disable=E1101