From d6e157b74d84da461cfb0039dc193299f96d5f0d Mon Sep 17 00:00:00 2001
From: Andrey Somov <public.somov@gmail.com>
Date: Fri, 2 Mar 2018 10:18:32 +0100
Subject: [PATCH] Revert "Allow colon in a plain scalar in a flow context
 (#45)"

This reverts commit c5b135fe39d41cffbdc006f28ccb2032df6005e0.
---
 lib/yaml/scanner.py                           | 16 +++++++++++-----
 lib3/yaml/scanner.py                          | 16 +++++++++++-----
 tests/data/colon-in-flow-context.loader-error |  1 +
 3 files changed, 23 insertions(+), 10 deletions(-)
 create mode 100644 tests/data/colon-in-flow-context.loader-error

diff --git a/lib/yaml/scanner.py b/lib/yaml/scanner.py
index f86cb80b..d191c905 100644
--- a/lib/yaml/scanner.py
+++ b/lib/yaml/scanner.py
@@ -1272,7 +1272,7 @@ def scan_flow_scalar_breaks(self, double, start_mark):
     def scan_plain(self):
         # See the specification for details.
         # We add an additional restriction for the flow context:
-        #   plain scalars in the flow context cannot contain ',' or '?'.
+        #   plain scalars in the flow context cannot contain ',', ':' and '?'.
         # We also keep track of the `allow_simple_key` flag here.
         # Indentation rules are loosed for the flow context.
         chunks = []
@@ -1291,12 +1291,18 @@ def scan_plain(self):
             while True:
                 ch = self.peek(length)
                 if ch in u'\0 \t\r\n\x85\u2028\u2029'   \
-                        or (ch == u':' and
-                                self.peek(length+1) in u'\0 \t\r\n\x85\u2028\u2029'
-                                      + (u',[]{}' if self.flow_level else u''))\
-                        or (self.flow_level and ch in u',?[]{}'):
+                        or (not self.flow_level and ch == u':' and
+                                self.peek(length+1) in u'\0 \t\r\n\x85\u2028\u2029') \
+                        or (self.flow_level and ch in u',:?[]{}'):
                     break
                 length += 1
+            # It's not clear what we should do with ':' in the flow context.
+            if (self.flow_level and ch == u':'
+                    and self.peek(length+1) not in u'\0 \t\r\n\x85\u2028\u2029,[]{}'):
+                self.forward(length)
+                raise ScannerError("while scanning a plain scalar", start_mark,
+                    "found unexpected ':'", self.get_mark(),
+                    "Please check http://pyyaml.org/wiki/YAMLColonInFlowContext for details.")
             if length == 0:
                 break
             self.allow_simple_key = False
diff --git a/lib3/yaml/scanner.py b/lib3/yaml/scanner.py
index 3b494072..1107f107 100644
--- a/lib3/yaml/scanner.py
+++ b/lib3/yaml/scanner.py
@@ -1266,7 +1266,7 @@ def scan_flow_scalar_breaks(self, double, start_mark):
     def scan_plain(self):
         # See the specification for details.
         # We add an additional restriction for the flow context:
-        #   plain scalars in the flow context cannot contain ',' or '?'.
+        #   plain scalars in the flow context cannot contain ',', ':' and '?'.
         # We also keep track of the `allow_simple_key` flag here.
         # Indentation rules are loosed for the flow context.
         chunks = []
@@ -1285,12 +1285,18 @@ def scan_plain(self):
             while True:
                 ch = self.peek(length)
                 if ch in '\0 \t\r\n\x85\u2028\u2029'    \
-                        or (ch == ':' and
-                                self.peek(length+1) in '\0 \t\r\n\x85\u2028\u2029'
-                                      + (u',[]{}' if self.flow_level else u''))\
-                        or (self.flow_level and ch in ',?[]{}'):
+                        or (not self.flow_level and ch == ':' and
+                                self.peek(length+1) in '\0 \t\r\n\x85\u2028\u2029') \
+                        or (self.flow_level and ch in ',:?[]{}'):
                     break
                 length += 1
+            # It's not clear what we should do with ':' in the flow context.
+            if (self.flow_level and ch == ':'
+                    and self.peek(length+1) not in '\0 \t\r\n\x85\u2028\u2029,[]{}'):
+                self.forward(length)
+                raise ScannerError("while scanning a plain scalar", start_mark,
+                    "found unexpected ':'", self.get_mark(),
+                    "Please check http://pyyaml.org/wiki/YAMLColonInFlowContext for details.")
             if length == 0:
                 break
             self.allow_simple_key = False
diff --git a/tests/data/colon-in-flow-context.loader-error b/tests/data/colon-in-flow-context.loader-error
new file mode 100644
index 00000000..13d50875
--- /dev/null
+++ b/tests/data/colon-in-flow-context.loader-error
@@ -0,0 +1 @@
+{ foo:bar }