From f3914eb16d28ad9eb20fe5133d9aa83658bcc27f Mon Sep 17 00:00:00 2001
From: Victor Stinner <victor.stinner@gmail.com>
Date: Wed, 20 Jan 2016 12:16:21 +0100
Subject: co_lnotab supports negative line number delta

Issue #26107: The format of the co_lnotab attribute of code objects changes to
support negative line number delta.

Changes:

* assemble_lnotab(): if line number delta is less than -128 or greater than
  127, emit multiple (offset_delta, lineno_delta) in co_lnotab
* update functions decoding co_lnotab to use signed 8-bit integers

  - dis.findlinestarts()
  - PyCode_Addr2Line()
  - _PyCode_CheckLineNumber()
  - frame_setlineno()

* update lnotab_notes.txt
* increase importlib MAGIC_NUMBER to 3361
* document the change in What's New in Python 3.6
* cleanup also PyCode_Optimize() to use better variable names
---
 Objects/codeobject.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

(limited to 'Objects/codeobject.c')

diff --git a/Objects/codeobject.c b/Objects/codeobject.c
index b0e34468a7..0f03dfe4b3 100644
--- a/Objects/codeobject.c
+++ b/Objects/codeobject.c
@@ -557,7 +557,8 @@ PyCode_Addr2Line(PyCodeObject *co, int addrq)
         addr += *p++;
         if (addr > addrq)
             break;
-        line += *p++;
+        line += (signed char)*p;
+        p++;
     }
     return line;
 }
@@ -592,17 +593,19 @@ _PyCode_CheckLineNumber(PyCodeObject* co, int lasti, PyAddrPair *bounds)
         if (addr + *p > lasti)
             break;
         addr += *p++;
-        if (*p)
+        if ((signed char)*p)
             bounds->ap_lower = addr;
-        line += *p++;
+        line += (signed char)*p;
+        p++;
         --size;
     }
 
     if (size > 0) {
         while (--size >= 0) {
             addr += *p++;
-            if (*p++)
+            if ((signed char)*p)
                 break;
+            p++;
         }
         bounds->ap_upper = addr;
     }
-- 
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