Fix running some file formats from the Downloads folder

Common/File/AndroidContentURI.cpp

@@ -62,7 +62,16 @@ AndroidContentURI AndroidContentURI::WithRootFilePath(const std::string &filePat
 
 AndroidContentURI AndroidContentURI::WithComponent(const std::string &filePath) {
 	AndroidContentURI uri = *this;
-	uri.file = uri.file + "/" + filePath;
+	if (uri.file.empty()) {
+		// Not sure what to do.
+		return uri;
+	}
+	if (uri.file.back() == ':') {
+		// Special case handling for Document URIs: Treat the ':' as a directory separator too (but preserved in the filename).
+		uri.file = uri.file + filePath;
+	} else {
+		uri.file = uri.file + "/" + filePath;
+	}
 	return uri;
 }
 
@@ -94,10 +103,11 @@ AndroidContentURI AndroidContentURI::WithReplacedExtension(const std::string &ne
 }
 
 bool AndroidContentURI::CanNavigateUp() const {
-	if (root.empty()) {
-		return false;
+	if (IsTreeURI()) {
+		return file.size() > root.size();
+	} else {
+		return file.find(':') != std::string::npos && file.back() != ':';
 	}
-	return file.size() > root.size();
 }
 
 // Only goes downwards in hierarchies. No ".." will ever be generated.
@@ -141,12 +151,20 @@ std::string AndroidContentURI::GetLastPart() const {
 		if (colon == std::string::npos) {
 			return std::string();
 		}
+		if (file.back() == ':') {
+			return file;
+		}
 		return file.substr(colon + 1);
 	}
 
 	size_t slash = file.rfind('/');
 	if (slash == std::string::npos) {
-		return std::string();
+		// ok, look for the final colon. If it's the last char, we would have been caught above in !CanNavigateUp.
+		size_t colon = file.rfind(':');
+		if (colon == std::string::npos) {
+			return std::string();
+		}
+		return file.substr(colon + 1);
 	}
 
 	std::string part = file.substr(slash + 1);
@@ -160,7 +178,13 @@ bool AndroidContentURI::NavigateUp() {
 
 	size_t slash = file.rfind('/');
 	if (slash == std::string::npos) {
-		return false;
+		// ok, look for the final colon.
+		size_t colon = file.rfind(':');
+		if (colon == std::string::npos) {
+			return false;
+		}
+		file = file.substr(0, colon + 1);  // Note: we include the colon in these paths.
+		return true;
 	}
 
 	file = file.substr(0, slash);

Common/File/AndroidContentURI.h

@@ -66,4 +66,8 @@ class AndroidContentURI {
 	const std::string &RootPath() const {
 		return root.empty() ? file : root;
 	}
+
+	bool IsTreeURI() const {
+		return !root.empty();
+	}
 };

unittest/UnitTest.cpp

@@ -722,14 +722,20 @@ static bool TestAndroidContentURI() {
 	EXPECT_EQ_STR(diff, std::string("Tekken 6.iso"));
 
 	EXPECT_EQ_STR(fileURI.GetFileExtension(), std::string(".prx"));
-	EXPECT_FALSE(fileURI.CanNavigateUp());
+	EXPECT_TRUE(fileURI.CanNavigateUp());  // Can now virtually navigate up one step from these.
 
-	// These are annoying because they hide the actual filename, and we can't get at a parent folder,
-	// which confuses our elf loading.
+	// These are annoying because they hide the actual filename, and we can't get at a parent folder.
+	// Decided to handle the ':' as a directory separator for navigation purposes, which fixes the problem (though not the extension thing).
 	AndroidContentURI downloadURI;
 	EXPECT_TRUE(downloadURI.Parse(std::string(downloadURIString)));
 	EXPECT_EQ_STR(downloadURI.GetLastPart(), std::string("10000000006"));
-	EXPECT_FALSE(downloadURI.CanNavigateUp());
+	EXPECT_TRUE(downloadURI.CanNavigateUp());
+	EXPECT_TRUE(downloadURI.NavigateUp());
+	// While this is not an openable valid content URI, we can still get something that we can concatenate a filename on top of.
+	EXPECT_EQ_STR(downloadURI.ToString(), std::string("content://com.android.providers.downloads.documents/document/msf%3A"));
+	EXPECT_EQ_STR(downloadURI.GetLastPart(), std::string("msf:"));
+	downloadURI = downloadURI.WithComponent("myfile");
+	EXPECT_EQ_STR(downloadURI.ToString(), std::string("content://com.android.providers.downloads.documents/document/msf%3Amyfile"));
 	return true;
 }