Issue #16121: Fix line number accounting in shlex

1 files changed, 15 insertions, 1 deletions

diff --git a/Lib/shlex.py b/Lib/shlex.py
index 3edd3db1ed..b9fd1dd9d8 100644
--- a/Lib/shlex.py
+++ b/Lib/shlex.py
@@ -44,6 +44,7 @@ class shlex:
         self.state = ' '
         self.pushback = deque()
         self.lineno = 1
+        self._lines_found = 0
         self.debug = 0
         self.token = ''
         self.filestack = deque()
@@ -114,12 +115,23 @@ class shlex:
         return raw
 
     def read_token(self):
+        if self._lines_found:
+            self.lineno += self._lines_found
+            self._lines_found = 0
+
+        i = 0
         quoted = False
         escapedstate = ' '
         while True:
+            i += 1
             nextchar = self.instream.read(1)
             if nextchar == '\n':
-                self.lineno = self.lineno + 1
+                # In case newline is the first character increment lineno
+                if i == 1:
+                    self.lineno += 1
+                else:
+                    self._lines_found += 1
+
             if self.debug >= 3:
                 print("shlex: in state", repr(self.state), \
                       "I see character:", repr(nextchar))
@@ -139,6 +151,7 @@ class shlex:
                         continue
                 elif nextchar in self.commenters:
                     self.instream.readline()
+                    # Not considered a token so incrementing lineno directly
                     self.lineno = self.lineno + 1
                 elif self.posix and nextchar in self.escape:
                     escapedstate = 'a'
@@ -206,6 +219,7 @@ class shlex:
                         continue
                 elif nextchar in self.commenters:
                     self.instream.readline()
+                    # Not considered a token so incrementing lineno directly
                     self.lineno = self.lineno + 1
                     if self.posix:
                         self.state = ' '