# HG changeset patch
# User Matt Harbison <matt_harbison@yahoo.com>
# Date 2020-11-21 21:20:49
# Node ID 2960b7fac966193436266a02230f3bc996e768bd
# Parent  bd22900e26acc1a8b67977dc5983df795785e524

setup: copy pythonXY.dll next to the hg.exe wrapper when building

This avoids the problem of having the newly built binary complaining that it
can't find the DLL.  There is an option in the python.org installer to add the
python install to PATH (which defaulted to "on" with py2, and therefore was not
an issue up to this point), but that makes switching between python versions
harder.

This shouldn't be an issue with the PyOxidizer binary, but that current has
issues running some of the tests, and took noticeably longer to build last time
I tried it.

Differential Revision: https://phab.mercurial-scm.org/D9362

diff --git a/setup.py b/setup.py
--- a/setup.py
+++ b/setup.py
@@ -782,6 +782,9 @@ class buildhgexe(build_ext):
 
         pythonlib = None
 
+        dir = os.path.dirname(self.get_ext_fullpath('dummy'))
+        self.hgtarget = os.path.join(dir, 'hg')
+
         if getattr(sys, 'dllhandle', None):
             # Different Python installs can have different Python library
             # names. e.g. the official CPython distribution uses pythonXY.dll
@@ -807,6 +810,19 @@ class buildhgexe(build_ext):
                     )
                 pythonlib = dllbasename[:-4]
 
+                # Copy the pythonXY.dll next to the binary so that it runs
+                # without tampering with PATH.
+                fsdecode = lambda x: x
+                if sys.version_info[0] >= 3:
+                    fsdecode = os.fsdecode
+                dest = os.path.join(
+                    os.path.dirname(self.hgtarget),
+                    fsdecode(dllbasename),
+                )
+
+                if not os.path.exists(dest):
+                    shutil.copy(buf.value, dest)
+
         if not pythonlib:
             log.warn(
                 'could not determine Python DLL filename; assuming pythonXY'
@@ -829,8 +845,6 @@ class buildhgexe(build_ext):
             output_dir=self.build_temp,
             macros=macros,
         )
-        dir = os.path.dirname(self.get_ext_fullpath('dummy'))
-        self.hgtarget = os.path.join(dir, 'hg')
         self.compiler.link_executable(
             objects, self.hgtarget, libraries=[], output_dir=self.build_temp
         )