From 63fc55b2eab0331465605a49bfd28a1bcb997f92 Mon Sep 17 00:00:00 2001
From: Ned Deily <nad@python.org>
Date: Mon, 8 Jun 2020 03:52:43 -0400
Subject: [PATCH] allow macOS installer builds to package pre-built html docs
 (GH-20715)

build-installer now looks in its directory of source tarballs
for a suitable html tarball of the same version.  If so, it
will unpack and use it rather than rebuilding the html format
documentation set from the source repo.  This is intended as
a speedup for test builds of the installer.  Files names must
be in the same format as produced by the docs build for download,
for example, `python-3.9.0b1-docs-html.tar.bz2`.
---
 Mac/BuildScript/build-installer.py | 40 ++++++++++++++++++++++++------
 1 file changed, 33 insertions(+), 7 deletions(-)

diff --git a/Mac/BuildScript/build-installer.py b/Mac/BuildScript/build-installer.py
index 86a09ae5254..a2cba321021 100755
--- a/Mac/BuildScript/build-installer.py
+++ b/Mac/BuildScript/build-installer.py
@@ -1066,14 +1066,40 @@ def buildPythonDocs():
     curDir = os.getcwd()
     os.chdir(buildDir)
     runCommand('make clean')
-    # Create virtual environment for docs builds with blurb and sphinx
-    runCommand('make venv')
-    runCommand('venv/bin/python3 -m pip install -U Sphinx==2.2.0')
-    runCommand('make html PYTHON=venv/bin/python')
+
+    # Search third-party source directory for a pre-built version of the docs.
+    #   Use the naming convention of the docs.python.org html downloads:
+    #       python-3.9.0b1-docs-html.tar.bz2
+    doctarfiles = [ f for f in os.listdir(DEPSRC)
+        if f.startswith('python-'+getFullVersion())
+        if f.endswith('-docs-html.tar.bz2') ]
+    if doctarfiles:
+        doctarfile = doctarfiles[0]
+        if not os.path.exists('build'):
+            os.mkdir('build')
+        # if build directory existed, it was emptied by make clean, above
+        os.chdir('build')
+        # Extract the first archive found for this version into build
+        runCommand('tar xjf %s'%shellQuote(os.path.join(DEPSRC, doctarfile)))
+        # see if tar extracted a directory ending in -docs-html
+        archivefiles = [ f for f in os.listdir('.')
+            if f.endswith('-docs-html')
+            if os.path.isdir(f) ]
+        if archivefiles:
+            archivefile = archivefiles[0]
+            # make it our 'Docs/build/html' directory
+            print(' -- using pre-built python documentation from %s'%archivefile)
+            os.rename(archivefile, 'html')
+        os.chdir(buildDir)
+
+    htmlDir = os.path.join('build', 'html')
+    if not os.path.exists(htmlDir):
+        # Create virtual environment for docs builds with blurb and sphinx
+        runCommand('make venv')
+        runCommand('venv/bin/python3 -m pip install -U Sphinx==2.2.0')
+        runCommand('make html PYTHON=venv/bin/python')
+    os.rename(htmlDir, docdir)
     os.chdir(curDir)
-    if not os.path.exists(docdir):
-        os.mkdir(docdir)
-    os.rename(os.path.join(buildDir, 'build', 'html'), docdir)
 
 
 def buildPython():