From 1bbc83267f33471f25b885c5376b65316a6d1968 Mon Sep 17 00:00:00 2001
From: ptmcg <ptmcg@austin.rr.com>
Date: Wed, 27 Oct 2021 12:57:15 -0500
Subject: [PATCH] Fix whitespace skipping bug introduced while reverting
 LineStart() changes - Issue #319

---
 CHANGES            |  4 ++++
 pyparsing/core.py  |  9 +++++----
 tests/test_unit.py | 23 +++++++++++++----------
 3 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/CHANGES b/CHANGES
index 2d9225c9..c4c2ab94 100644
--- a/CHANGES
+++ b/CHANGES
@@ -6,6 +6,10 @@ Version 3.0.3 -
 ---------------
 - Fixed regex typo in `one_of` fix for `as_keyword=True`.
 
+- Fixed a whitespace-skipping bug, Issue #319, introduced as part of the revert
+  of the `LineStart` changes. Reported by Marc-Alexandre Côté,
+  thanks!
+
 
 Version 3.0.2 -
 ---------------
diff --git a/pyparsing/core.py b/pyparsing/core.py
index 0e91666a..ab178f32 100644
--- a/pyparsing/core.py
+++ b/pyparsing/core.py
@@ -3853,7 +3853,9 @@ def __init__(self, exprs: IterableType[ParserElement], savelist: bool = False):
     def streamline(self):
         super().streamline()
         if self.exprs:
+            self.mayReturnEmpty = any(e.mayReturnEmpty for e in self.exprs)
             self.saveAsList = any(e.saveAsList for e in self.exprs)
+            self.skipWhitespace = all(e.skipWhitespace for e in self.exprs)
         else:
             self.saveAsList = False
         return self
@@ -3967,7 +3969,7 @@ def _setResultsName(self, name, listAllMatches=False):
 
 class MatchFirst(ParseExpression):
     """Requires that at least one :class:`ParseExpression` is found. If
-    two expressions match, the first one listed is the one that will
+    more than one expression matches, the first one listed is the one that will
     match. May be constructed using the ``'|'`` operator.
 
     Example::
@@ -3987,7 +3989,6 @@ def __init__(self, exprs: IterableType[ParserElement], savelist: bool = False):
         super().__init__(exprs, savelist)
         if self.exprs:
             self.mayReturnEmpty = any(e.mayReturnEmpty for e in self.exprs)
-            self.callPreparse = all(e.callPreparse for e in self.exprs)
             self.skipWhitespace = all(e.skipWhitespace for e in self.exprs)
         else:
             self.mayReturnEmpty = True
@@ -4000,7 +4001,7 @@ def streamline(self):
         if self.exprs:
             self.saveAsList = any(e.saveAsList for e in self.exprs)
             self.mayReturnEmpty = any(e.mayReturnEmpty for e in self.exprs)
-            self.callPreparse = all(e.callPreparse for e in self.exprs)
+            self.skipWhitespace = all(e.skipWhitespace for e in self.exprs)
         else:
             self.saveAsList = False
             self.mayReturnEmpty = True
@@ -4013,7 +4014,7 @@ def parseImpl(self, instring, loc, doActions=True):
         for e in self.exprs:
             try:
                 return e._parse(
-                    instring, loc, doActions, callPreParse=not self.callPreparse
+                    instring, loc, doActions,
                 )
             except ParseFatalException as pfe:
                 pfe.__traceback__ = None
diff --git a/tests/test_unit.py b/tests/test_unit.py
index 0a954000..f90e42ac 100644
--- a/tests/test_unit.py
+++ b/tests/test_unit.py
@@ -3617,16 +3617,19 @@ def testLineStart2(self):
 
     def testLineStartWithLeadingSpaces(self):
         # testing issue #272
+        # reverted in 3.0.2 - LineStart() + expr will match expr even if there
+        # are leading spaces. To force "only at column 1" matching, use
+        # AtLineStart(expr).
         instring = dedent(
             """
-        a
-         b
-          c
-        d
-        e
-         f
-          g
-        """
+            a
+             b
+              c
+            d
+            e
+             f
+              g
+            """
         )
         print(pp.testing.with_line_numbers(instring))
 
@@ -7711,10 +7714,10 @@ def testEnableDebugWithCachedExpressionsMarkedWithAsterisk(self):
             Match leading_a at loc 1(1,2)
               aba
                ^
-            *Match A at loc 1(1,2)
+            Match A at loc 1(1,2)
               aba
                ^
-            *Match A failed, ParseException raised: Expected A, found 'ba'  (at char 1), (line:1, col:2)
+            Match A failed, ParseException raised: Expected A, found 'ba'  (at char 1), (line:1, col:2)
             Match leading_a failed, ParseException raised: Expected A, found 'ba'  (at char 1), (line:1, col:2)
             *Match B at loc 1(1,2)
               aba