Patchwork [1,of,2,STABLE] setup: add .dll to Python library name

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Submitter Gregory Szorc
Date April 26, 2016, 11:25 p.m.
Message ID <ba89075c616d56c3f1ce.1461713155@ubuntu-vm-main>
Download mbox | patch
Permalink /patch/14796/
State Superseded
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Gregory Szorc - April 26, 2016, 11:25 p.m.
# HG changeset patch
# User Gregory Szorc <gregory.szorc@gmail.com>
# Date 1461711788 25200
#      Tue Apr 26 16:03:08 2016 -0700
# Branch stable
# Node ID ba89075c616d56c3f1ce02c97103c6d0ff8aa006
# Parent  87d4a6c5567e81386b8c2209d95060d5bf72e064
setup: add .dll to Python library name

LoadLibrary() changes behavior depending on whether the argument
passed to it contains a period. From the MSDN docs:

If no file name extension is specified in the lpFileName parameter,
the default library extension .dll is appended. However, the file name
string can include a trailing point character (.) to indicate that the
module name has no extension. When no path is specified, the function
searches for loaded modules whose base name matches the base name of
the module to be loaded. If the name matches, the load succeeds.
Otherwise, the function searches for the file.

As the subsequent patch will show, some environments on Windows
define their Python library as e.g. "libpython2.7.dll." The existing
code would pass "libpython2.7" into LoadLibrary(). It would assume
"7" was the file extension and look for a "libpython2.dll" to load.

By passing ".dll" into LoadLibrary(), we force it to search for the
exact basename we want, even if it contains a period.

Patch

diff --git a/mercurial/exewrapper.c b/mercurial/exewrapper.c
--- a/mercurial/exewrapper.c
+++ b/mercurial/exewrapper.c
@@ -95,33 +95,33 @@  int main(int argc, char *argv[])
 		if (hfind != INVALID_HANDLE_VALUE) {
 			/* path pyhome exists, let's use it */
 			FindClose(hfind);
 			strcpy_s(pydllfile, sizeof(pydllfile), pyhome);
 			strcat_s(pydllfile, sizeof(pydllfile), "\\" HGPYTHONLIB);
 			pydll = LoadLibrary(pydllfile);
 			if (pydll == NULL) {
 				err = "failed to load private Python DLL "
-				      HGPYTHONLIB ".dll";
+				      HGPYTHONLIB;
 				goto bail;
 			}
 			Py_SetPythonHome = (void*)GetProcAddress(pydll,
 							"Py_SetPythonHome");
 			if (Py_SetPythonHome == NULL) {
 				err = "failed to get Py_SetPythonHome";
 				goto bail;
 			}
 			Py_SetPythonHome(pyhome);
 		}
 	}
 
 	if (pydll == NULL) {
 		pydll = LoadLibrary(HGPYTHONLIB);
 		if (pydll == NULL) {
-			err = "failed to load Python DLL " HGPYTHONLIB ".dll";
+			err = "failed to load Python DLL " HGPYTHONLIB;
 			goto bail;
 		}
 	}
 
 	Py_Main = (void*)GetProcAddress(pydll, "Py_Main");
 	if (Py_Main == NULL) {
 		err = "failed to get Py_Main";
 		goto bail;
diff --git a/setup.py b/setup.py
--- a/setup.py
+++ b/setup.py
@@ -365,17 +365,17 @@  class buildhgexe(build_ext):
 
     def build_extensions(self):
         if os.name != 'nt':
             return
         if isinstance(self.compiler, HackedMingw32CCompiler):
             self.compiler.compiler_so = self.compiler.compiler # no -mdll
             self.compiler.dll_libraries = [] # no -lmsrvc90
         hv = sys.hexversion
-        pythonlib = 'python%d%d' % (hv >> 24, (hv >> 16) & 0xff)
+        pythonlib = 'python%d%d.dll' % (hv >> 24, (hv >> 16) & 0xff)
         with open('mercurial/hgpythonlib.h', 'wb') as f:
             f.write('/* this file is autogenerated by setup.py */\n')
             f.write('#define HGPYTHONLIB "%s"\n' % pythonlib)
         objects = self.compiler.compile(['mercurial/exewrapper.c'],
                                          output_dir=self.build_temp)
         dir = os.path.dirname(self.get_ext_fullpath('dummy'))
         target = os.path.join(dir, 'hg')
         self.compiler.link_executable(objects, target,