bpo-34293: Fix PDF documentation paper size (GH-8585)

The "A4" pdfs were previously the wrong size due to a change in the options in Sphinx 1.5.

See also sphinx-doc/sphinx#5235

Doc/Makefile

@@ -13,7 +13,11 @@ SOURCES      =
 DISTVERSION  = $(shell $(PYTHON) tools/extensions/patchlevel.py)
 SPHINXERRORHANDLING = -W
 
-ALLSPHINXOPTS = -b $(BUILDER) -d build/doctrees -D latex_elements.papersize=$(PAPER) \
+# Internal variables.
+PAPEROPT_a4     = -D latex_elements.papersize=a4paper
+PAPEROPT_letter = -D latex_elements.papersize=letterpaper
+
+ALLSPHINXOPTS = -b $(BUILDER) -d build/doctrees $(PAPEROPT_$(PAPER)) \
                 $(SPHINXOPTS) $(SPHINXERRORHANDLING) . build/$(BUILDER) $(SOURCES)
 
 .PHONY: help build html htmlhelp latex text changes linkcheck \

Misc/NEWS.d/next/Documentation/2018-07-31-15-38-26.bpo-34293.yHupAL.rst

+Fix the Doc/Makefile regarding PAPER environment variable and PDF builds