Fix Unique Good, Bad. Simplify HTML parser.

Good and Bad should obviously do the exact opposite thing
to what they did.

4 files changed, 43 insertions, 47 deletions

diff --git a/c/data.cpp b/c/data.cpp
index df5627a..7ae6ad1 100644
--- a/c/data.cpp
+++ b/c/data.cpp
@@ -14,50 +14,44 @@
 static Unique<HINTERNET, InternetCloseHandle> s_hi =
 	InternetOpenW(L"Episode Browser", INTERNET_OPEN_TYPE_DIRECT, nullptr, nullptr, 0);
 
-/* ParsedDoc downloads and parses an HTML document. */
-struct ParsedDoc
+Unique<htmlParserCtxtPtr, xmlFreeParserCtxt> RemoteParserCtxt(const wchar_t* wszUrl, const char* szUrl)
 {
-	Unique<HINTERNET, InternetCloseHandle> hiUrl;
-	Unique<htmlParserCtxtPtr, xmlFreeParserCtxt> ctx;
-	char bufI[1024];
+	if (s_hi.Bad(0))
+		throw Win32Error();
+
+	Unique<HINTERNET, InternetCloseHandle> hiUrl = InternetOpenUrlW(
+	    s_hi.v, wszUrl, nullptr, 0, INTERNET_FLAG_NO_UI, 0);
+	if (hiUrl.Bad(0))
+		throw InternetError();
+
 	char bufX[1024];
+	Unique<htmlParserCtxtPtr, xmlFreeParserCtxt> ctx = htmlCreatePushParserCtxt(
+	    nullptr, nullptr, bufX, sizeof(bufX), szUrl, XML_CHAR_ENCODING_UTF8);
+	if (ctx.Bad(0))
+		throw XmlError();
 
-	ParsedDoc(const wchar_t* wszUrl, const char* szUrl)
-	{
-		if (!s_hi.Bad(0))
-			throw Win32Error();
+	htmlCtxtUseOptions(ctx.v, HTML_PARSE_RECOVER|HTML_PARSE_NOERROR|HTML_PARSE_NOWARNING);
 
-		hiUrl = InternetOpenUrlW(s_hi.v, wszUrl, nullptr, 0, INTERNET_FLAG_NO_UI, 0);
-		if (!hiUrl.Bad(0))
+	BOOL r;
+	DWORD cbRead;
+	char bufI[1024];
+	while (r = InternetReadFile(hiUrl.v, bufI, sizeof(bufI), &cbRead), cbRead) {
+		if (!r)
 			throw InternetError();
-
-		ctx = htmlCreatePushParserCtxt(nullptr, nullptr, bufX, sizeof(bufX), szUrl, XML_CHAR_ENCODING_UTF8);
-		if (!ctx.Bad(0))
+		if (!htmlParseChunk(ctx.v, bufI, cbRead, 0))
 			throw XmlError();
-
-		htmlCtxtUseOptions(ctx.v, HTML_PARSE_RECOVER|HTML_PARSE_NOERROR|HTML_PARSE_NOWARNING);
-
-		BOOL r;
-		DWORD cbRead;
-		while (r = InternetReadFile(hiUrl.v, bufI, sizeof(bufI), &cbRead), cbRead) {
-			if (!r)
-				throw InternetError();
-			if (!htmlParseChunk(ctx.v, bufI, cbRead, 0))
-				throw XmlError();
-		}
-		htmlParseChunk(ctx.v, bufI, 0, 1); /* Stop parsing. */
 	}
+	htmlParseChunk(ctx.v, bufI, 0, 1); /* Stop parsing. */
 
-	operator htmlDocPtr() { return ctx.v->myDoc; }
-};
+	return ctx;
+}
 
 static inline void XmlFree(void* p) { xmlFree(p); }
 
 template <size_t N>
-bool WcharsFromXmlchars(wchar_t (&dst)[N], xmlChar* utf8_)
+bool WcharsFromXmlchars(wchar_t (&dst)[N], Unique<xmlChar*, XmlFree> utf8)
 {
-	Unique<xmlChar*, XmlFree> utf8 = utf8_;
-	if (!utf8.Bad(0))
+	if (utf8.Bad(0))
 		throw XmlError();
 
 	/* Truncate if source is larger than destination. */
@@ -167,17 +161,18 @@ void FetchData(unsigned char* sig)
 	 * specific XPath query. This is fragile theoretically, but
 	 * unlikely to break practically. */
 
-	ParsedDoc doc(L"https://www.detectiveconanworld.com/wiki/Anime",
-	    "https://www.detectiveconanworld.com/wiki/Anime");
+	Unique<htmlParserCtxtPtr, xmlFreeParserCtxt> ctx =
+		RemoteParserCtxt(L"https://www.detectiveconanworld.com/wiki/Anime",
+		    "https://www.detectiveconanworld.com/wiki/Anime");
 
-	Unique<xmlXPathContextPtr, xmlXPathFreeContext> xpathCtx = xmlXPathNewContext(doc);
-	if (!xpathCtx.Bad(0))
+	Unique<xmlXPathContextPtr, xmlXPathFreeContext> xpathCtx = xmlXPathNewContext(ctx.v->myDoc);
+	if (xpathCtx.Bad(0))
 		throw XmlError();
 
 	Unique<xmlXPathObjectPtr, xmlXPathFreeObject> xpathObj = xmlXPathEvalExpression(
 	    reinterpret_cast<const xmlChar*>("//tr[./td[1] != '' and ./td[3][@style='background:#f2fde9;']]"),
 	    xpathCtx.v);
-	if (!xpathObj.Bad(0))
+	if (xpathObj.Bad(0))
 		throw XmlError();
 
 	xmlNodeSetPtr nodes = xpathObj.v->nodesetval;
@@ -269,16 +264,17 @@ void FetchScreenwriters(unsigned char* sig)
 		Wcscpy(Buf(url)+Len(prefix), d.wiki);
 
 		/* Retrieve screenwriter from HTML. */
-		ParsedDoc doc(url, nullptr);
-		Unique<xmlXPathContextPtr, xmlXPathFreeContext> xpathCtx = xmlXPathNewContext(doc);
-		if (!xpathCtx.Bad(0))
+
+		Unique<htmlParserCtxtPtr, xmlFreeParserCtxt> ctx = RemoteParserCtxt(url, nullptr);
+		Unique<xmlXPathContextPtr, xmlXPathFreeContext> xpathCtx = xmlXPathNewContext(ctx.v->myDoc);
+		if (xpathCtx.Bad(0))
 			throw XmlError();
 
 		Unique<xmlXPathObjectPtr, xmlXPathFreeObject> xpathObj =
 			xmlXPathEvalExpression(reinterpret_cast<const xmlChar*>(
 			    "//th[contains(text(), 'Screenplay:')]/following-sibling::td"),
 			    xpathCtx.v);
-		if (!xpathObj.Bad(0))
+		if (xpathObj.Bad(0))
 			throw XmlError();
 
 		xmlNodeSetPtr nodes = xpathObj.v->nodesetval;
diff --git a/c/data.h b/c/data.h
index 171edaa..0f00ecb 100644
--- a/c/data.h
+++ b/c/data.h
@@ -120,11 +120,11 @@ struct FileView
 	{
 		hf = CreateFile(filename, GENERIC_READ|GENERIC_WRITE,
 		    0, nullptr, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, nullptr);
-		if (!hf.Bad(INVALID_HANDLE_VALUE)) {
+		if (hf.Bad(INVALID_HANDLE_VALUE)) {
 			if (GetLastError() == ERROR_FILE_NOT_FOUND) {
 				hf = CreateFile(filename, GENERIC_READ|GENERIC_WRITE,
 				    0, nullptr, CREATE_NEW, FILE_ATTRIBUTE_NORMAL, nullptr);
-				if (!hf.Bad(INVALID_HANDLE_VALUE))
+				if (hf.Bad(INVALID_HANDLE_VALUE))
 					throw Win32Error();
 			} else
 				throw Win32Error();
@@ -134,11 +134,11 @@ struct FileView
 		cbMap.QuadPart = c*sizeof(T);
 		hm = CreateFileMapping(hf.v, nullptr, PAGE_READWRITE,
 		    cbMap.HighPart, cbMap.LowPart, nullptr);
-		if (!hm.Bad(0))
+		if (hm.Bad(0))
 			throw Win32Error();
 
 		view = reinterpret_cast<T*>(MapViewOfFile(hm.v, FILE_MAP_ALL_ACCESS, 0, 0, 0));
-		if (!view.Bad(0))
+		if (view.Bad(0))
 			throw Win32Error();
 	}
 
diff --git a/c/ext.cpp b/c/ext.cpp
index 8e58ade..694581d 100644
--- a/c/ext.cpp
+++ b/c/ext.cpp
@@ -87,7 +87,7 @@ static bool FindMatchingFile(wchar_t (&file)[MAX_PATH], const wchar_t* const roo
 
 	WIN32_FIND_DATA fdata;
 	Unique<HANDLE, FindClose> h = FindFirstFileW(pat, &fdata);
-	if (!h.Bad(INVALID_HANDLE_VALUE))
+	if (h.Bad(INVALID_HANDLE_VALUE))
 		throw Win32Error();
 
 	do
diff --git a/c/util.h b/c/util.h
index f9e3057..7ed7636 100644
--- a/c/util.h
+++ b/c/util.h
@@ -72,11 +72,11 @@ struct Unique
 	}
 	bool Good(T u) noexcept
 	{
-		return ok = v == u;
+		return !(ok = v == u);
 	}
 	bool Bad(T u) noexcept
 	{
-		return ok = v != u;
+		return !(ok = v != u);
 	}
 	~Unique()
 	{