From d161aa6490d874d20f46d28f1df410e4b11fcd8c Mon Sep 17 00:00:00 2001
From: Wenzel Jakob <wenzel@cs.cornell.edu>
Date: Sat, 20 Oct 2012 18:08:36 -0400
Subject: [PATCH] futher Linux Python auto-configuration improvements

---
 doc/python.tex            |  5 +----
 src/libcore/fresolver.cpp | 23 +++++++++++++----------
 src/libpython/core.cpp    | 24 ++++++++++++++++--------
 3 files changed, 30 insertions(+), 22 deletions(-)

diff --git a/doc/python.tex b/doc/python.tex
index 51d15c63..594a494c 100644
--- a/doc/python.tex
+++ b/doc/python.tex
@@ -66,10 +66,7 @@ from mitsuba.render import SceneHandler
 # Get a reference to the thread's file resolver
 fileResolver = Thread.getThread().getFileResolver()
 
-# Register the search path needed to load plugins
-fileResolver.appendPath('<path to mitsuba directory>')
-
-# Register the search path needed to load scene resources
+# Register any searchs path needed to load scene resources (optional)
 fileResolver.appendPath('<path to scene directory>')
 
 # Optional: supply parameters that can be accessed 
diff --git a/src/libcore/fresolver.cpp b/src/libcore/fresolver.cpp
index d66444f8..80cf0ba4 100644
--- a/src/libcore/fresolver.cpp
+++ b/src/libcore/fresolver.cpp
@@ -10,16 +10,19 @@ MTS_NAMESPACE_BEGIN
 FileResolver::FileResolver() {
 	m_paths.push_back(fs::current_path());
 #if defined(__LINUX__)
-	char exePath[PATH_MAX];
-	memset(exePath, 0, PATH_MAX);
-	if (readlink("/proc/self/exe", exePath, PATH_MAX) != -1) {
-		const fs::path exeParentPath = fs::path(exePath).parent_path();
-		prependPath(exeParentPath);
-		// Handle local installs: ~/local/bin/:~/local/share/mitsuba/*
-		fs::path sharedDir = exeParentPath.parent_path();
-		sharedDir /= fs::path("share/mitsuba");
-		if (fs::exists(sharedDir)) {
-			prependPath(sharedDir);
+	char exePathTemp[PATH_MAX];
+	memset(exePathTemp, 0, PATH_MAX);
+	if (readlink("/proc/self/exe", exePathTemp, PATH_MAX) != -1) {
+		fs::path exePath(exePathTemp);
+
+		/* Make sure that we're not running inside a Python interpreter */
+		if (exePath.filename().string().find("python") == std::string::npos) {
+			prependPath(exePath.parent_path());
+			// Handle local installs: ~/local/bin/:~/local/share/mitsuba/*
+			fs::path sharedDir = exePath.parent_path().parent_path()
+				/ fs::path("share") / fs::path("mitsuba");
+			if (fs::exists(sharedDir))
+				prependPath(sharedDir);
 		}
 	} else {
 		Log(EError, "Could not detect the executable path!");
diff --git a/src/libpython/core.cpp b/src/libpython/core.cpp
index 8c0ad7c9..3c6ca52b 100644
--- a/src/libpython/core.cpp
+++ b/src/libpython/core.cpp
@@ -47,26 +47,34 @@ void initializeFramework() {
 	SHVector::staticInitialization();
 	SceneHandler::staticInitialization();
 
-	fs::path sharedLibraryPath;
+	fs::path basePath;
 
-	/* Try to detect the python plugin path */
+	/* Try to detect the base path of the Mitsuba installation */
 	#if defined(__LINUX__)
 		Dl_info info;
 		dladdr((void *) &initializeFramework, &info);
-		if (info.dli_fname)
-			sharedLibraryPath = fs::path(info.dli_fname);
+		if (info.dli_fname) {
+			/* Try to detect a few default setups */
+			if (boost::starts_with(info.dli_fname, "/usr/lib")) {
+				basePath = fs::path("/usr/share/mitsuba");
+			} else if (boost::starts_with(info.dli_fname, "/usr/local/lib")) {
+				basePath = fs::path("/usr/local/share/mitsuba");
+			} else {
+				/* This is a locally-compiled repository */
+				basePath = fs::path(info.dli_fname).parent_path().parent_path().parent_path();
+			}
+		}
 	#elif defined(__OSX__)
 		uint32_t imageCount = _dyld_image_count();
 		for (uint32_t i=0; i<imageCount; ++i) {
 			const char *imageName = _dyld_get_image_name(i);
 			if (boost::ends_with(imageName, "mitsuba.so"))
-				sharedLibraryPath = fs::path(imageName);
+				basePath = fs::path(imageName).parent_path().parent_path().parent_path();
 		}
 	#endif
 
-	if (!sharedLibraryPath.empty())
-		Thread::getThread()->getFileResolver()->prependPath(
-			sharedLibraryPath.parent_path().parent_path().parent_path());
+	if (!basePath.empty())
+		Thread::getThread()->getFileResolver()->prependPath(basePath);
 }
 
 void shutdownFramework() {