[Python-checkins] bpo-46784: Add newly exported expat symbols to the namespace. (GH-31397)

[miss-islington]

https://github.com/python/cpython/commit/9aca412db8343702d9199c31ba73519e6f8823b5
commit: 9aca412db8343702d9199c31ba73519e6f8823b5
branch: 3.9
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: miss-islington <31488909+miss-islington at users.noreply.github.com>
date: 2022-02-18T15:13:16-08:00
summary:

bpo-46784: Add newly exported expat symbols to the namespace. (GH-31397)


The libexpat 2.4.1 upgrade from  introduced the following new exported symbols:

* `testingAccountingGetCountBytesDirect`
* `testingAccountingGetCountBytesIndirect`
* `unsignedCharToPrintable`
* `XML_SetBillionLaughsAttackProtectionActivationThreshold`
* `XML_SetBillionLaughsAttackProtectionMaximumAmplification`

We need to adjust [Modules/expat/pyexpatns.h](https://github.com/python/cpython/blob/master/Modules/expat/pyexpatns.h)

(The newer libexpat upgrade  has no new symbols).

Automerge-Triggered-By: GH:gpshead
(cherry picked from commit 6312c1052c0186b4596fc45c42fd3ade9f8f5911)

Co-authored-by: Yilei "Dolee" Yang <yileiyang at google.com>

files:
A Misc/NEWS.d/next/Library/2022-02-18-22-10-30.bpo-46784.SVOQJx.rst
M Modules/expat/pyexpatns.h

diff --git a/Misc/NEWS.d/next/Library/2022-02-18-22-10-30.bpo-46784.SVOQJx.rst b/Misc/NEWS.d/next/Library/2022-02-18-22-10-30.bpo-46784.SVOQJx.rst
new file mode 100644
index 0000000000000..d190816637ae8
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2022-02-18-22-10-30.bpo-46784.SVOQJx.rst
@@ -0,0 +1 @@
+Fix libexpat symbols collisions with user dynamically loaded or statically linked libexpat in embedded Python.
diff --git a/Modules/expat/pyexpatns.h b/Modules/expat/pyexpatns.h
index cfb742ee000b0..d45d9b6c45715 100644
--- a/Modules/expat/pyexpatns.h
+++ b/Modules/expat/pyexpatns.h
@@ -38,6 +38,9 @@
 #ifndef PYEXPATNS_H
 #define PYEXPATNS_H
 
+#define testingAccountingGetCountBytesDirect PyExpat_testingAccountingGetCountBytesDirect
+#define testingAccountingGetCountBytesIndirect PyExpat_testingAccountingGetCountBytesIndirect
+#define unsignedCharToPrintable PyExpat_unsignedCharToPrintable
 #define XML_DefaultCurrent              PyExpat_XML_DefaultCurrent
 #define XML_ErrorString                 PyExpat_XML_ErrorString
 #define XML_ExpatVersion                PyExpat_XML_ExpatVersion
@@ -81,6 +84,8 @@
 #define XML_ResumeParser                PyExpat_XML_ResumeParser
 #define XML_SetAttlistDeclHandler       PyExpat_XML_SetAttlistDeclHandler
 #define XML_SetBase                     PyExpat_XML_SetBase
+#define XML_SetBillionLaughsAttackProtectionActivationThreshold PyExpat_XML_SetBillionLaughsAttackProtectionActivationThreshold
+#define XML_SetBillionLaughsAttackProtectionMaximumAmplification PyExpat_XML_SetBillionLaughsAttackProtectionMaximumAmplification
 #define XML_SetCdataSectionHandler      PyExpat_XML_SetCdataSectionHandler
 #define XML_SetCharacterDataHandler     PyExpat_XML_SetCharacterDataHandler
 #define XML_SetCommentHandler           PyExpat_XML_SetCommentHandler