io: Always use unbuffered input

Before, we often used unbuffered input via the lzma or gzip handlers,
more or less inadvertently.

Change the default file handlers from buffered (stdc FILE) to unbuffered
(POSIX fds).

include/libxml/xmlIO.h

@@ -347,19 +347,24 @@ XMLPUBFUN xmlParserInputPtr
 XMLPUBFUN xmlChar *
 	xmlNormalizeWindowsPath		(const xmlChar *path);
 
+XML_DEPRECATED
 XMLPUBFUN int
 	xmlCheckFilename		(const char *path);
 /**
  * Default 'file://' protocol callbacks
  */
+XML_DEPRECATED
 XMLPUBFUN int
 	xmlFileMatch			(const char *filename);
+XML_DEPRECATED
 XMLPUBFUN void *
 	xmlFileOpen			(const char *filename);
+XML_DEPRECATED
 XMLPUBFUN int
 	xmlFileRead			(void * context,
 					 char * buffer,
 					 int len);
+XML_DEPRECATED
 XMLPUBFUN int
 	xmlFileClose			(void * context);
 

python/generator.py

@@ -298,6 +298,7 @@ deprecated_funcs = {
     'namePush': True,
     'nodePop': True,
     'nodePush': True,
+    'xmlCheckFilename': True,
     'xmlCheckLanguageID': True,
     'xmlCleanupCharEncodingHandlers': True,
     'xmlCleanupGlobals': True,
@@ -305,6 +306,7 @@ deprecated_funcs = {
     'xmlDecodeEntities': True,
     'xmlDictCleanup': True,
     'xmlEncodeEntities': True,
+    'xmlFileMatch': True,
     'xmlHandleEntity': True,
     'xmlInitCharEncodingHandlers': True,
     'xmlInitGlobals': True,

xmlIO.c

@@ -36,18 +36,6 @@
 #include <direct.h>
 #endif
 
-#ifndef S_ISDIR
-#  ifdef _S_ISDIR
-#    define S_ISDIR(x) _S_ISDIR(x)
-#  elif defined(S_IFDIR)
-#    ifdef S_IFMT
-#      define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
-#    elif defined(_S_IFMT)
-#      define S_ISDIR(m) (((m) & _S_IFMT) == S_IFDIR)
-#    endif
-#  endif
-#endif
-
 #include <libxml/xmlIO.h>
 #include <libxml/xmlmemory.h>
 #include <libxml/parser.h>
@@ -70,6 +58,22 @@
 
 #define MINLEN 4000
 
+#ifndef STDIN_FILENO
+  #define STDIN_FILENO 0
+#endif
+
+#ifndef S_ISDIR
+#  ifdef _S_ISDIR
+#    define S_ISDIR(x) _S_ISDIR(x)
+#  elif defined(S_IFDIR)
+#    ifdef S_IFMT
+#      define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
+#    elif defined(_S_IFMT)
+#      define S_ISDIR(m) (((m) & _S_IFMT) == S_IFDIR)
+#    endif
+#  endif
+#endif
+
 /*
  * Input I/O callback sets
  */
@@ -628,8 +632,7 @@ xmlWrapStatUtf8(const char *path, struct _stat *info) {
  * xmlCheckFilename:
  * @path:  the path to check
  *
- * function checks to see if @path is a valid source
- * (file, socket...) for XML.
+ * DEPRECATED: Internal function, don't use.
  *
  * if stat is not available on the target machine,
  * returns 1.  if stat fails, returns 0 (if calling
@@ -675,6 +678,100 @@ xmlCheckFilename (const char *path)
     return 1;
 }
 
+/**
+ * xmlFdOpen:
+ * @filename:  the URI for matching
+ * @out:  pointer to resulting context
+ *
+ * Returns an xmlParserErrors code
+ */
+static int
+xmlFdOpen(const char *filename, void **out) {
+    const char *escaped = NULL;
+    char *unescaped = NULL;
+    int fd;
+    int ret;
+
+    *out = (void *) 0;
+    if (filename == NULL)
+        return(XML_ERR_ARGUMENT);
+
+    if (!strcmp(filename, "-")) {
+        *out = (void *) (ptrdiff_t) STDIN_FILENO;
+	return(XML_ERR_OK);
+    }
+
+    /*
+     * TODO: This should be moved to uri.c. We also need support for
+     * UNC paths on Windows.
+     */
+    if (!xmlStrncasecmp(BAD_CAST filename, BAD_CAST "file://localhost/", 17)) {
+#if defined (_WIN32)
+	escaped = &filename[17];
+#else
+	escaped = &filename[16];
+#endif
+    } else if (!xmlStrncasecmp(BAD_CAST filename, BAD_CAST "file:///", 8)) {
+#if defined (_WIN32)
+	escaped = &filename[8];
+#else
+	escaped = &filename[7];
+#endif
+    } else if (!xmlStrncasecmp(BAD_CAST filename, BAD_CAST "file:/", 6)) {
+        /* lots of generators seems to lazy to read RFC 1738 */
+#if defined (_WIN32)
+	escaped = &filename[6];
+#else
+	escaped = &filename[5];
+#endif
+    }
+
+    if (escaped != NULL) {
+        unescaped = xmlURIUnescapeString(escaped, 0, NULL);
+        if (unescaped == NULL)
+            return(XML_ERR_NO_MEMORY);
+        filename = unescaped;
+    }
+
+#if defined(_WIN32)
+    {
+        wchar_t *wpath;
+
+        wpath = __xmlIOWin32UTF8ToWChar(filename);
+        if (wpath == NULL)
+            return(XML_ERR_NO_MEMORY);
+	fd = _wopen(wpath, _O_RDONLY | _O_BINARY);
+        xmlFree(wpath);
+    }
+#else
+    fd = open(filename, O_RDONLY);
+#endif /* WIN32 */
+
+    if (fd < 0) {
+        /*
+         * Windows and possibly other platforms return EINVAL
+         * for invalid filenames.
+         */
+        if ((errno == ENOENT) || (errno == EINVAL)) {
+            ret = XML_IO_ENOENT;
+        } else {
+            /*
+             * This error won't be forwarded to the parser context
+             * which will report it a second time.
+             */
+            ret = xmlIOErr(0, filename);
+        }
+    } else {
+        *out = (void *) (ptrdiff_t) fd;
+        ret = XML_ERR_OK;
+    }
+
+    if (unescaped != NULL)
+        xmlFree(unescaped);
+
+    return(ret);
+}
+
 /**
  * xmlFdRead:
  * @context:  the I/O context
@@ -737,7 +834,7 @@ xmlFdClose (void * context) {
  * xmlFileMatch:
  * @filename:  the URI for matching
  *
- * input from FILE *
+ * DEPRECATED: Internal function, don't use.
  *
  * Returns 1 if matches, 0 otherwise
  */
@@ -852,7 +949,7 @@ xmlFileOpenSafe(const char *filename, void **out) {
  * xmlFileOpen:
  * @filename:  the URI for matching
  *
- * Open a file.
+ * DEPRECATED: Internal function, don't use.
  *
  * Returns an IO context or NULL in case or failure
  */
@@ -921,7 +1018,7 @@ xmlFileOpenW (const char *filename) {
  * @buffer:  where to drop data
  * @len:  number of bytes to write
  *
- * Read @len bytes to @buffer from the I/O channel.
+ * DEPRECATED: Internal function, don't use.
  *
  * Returns the number of bytes written or < 0 in case of failure
  */
@@ -965,7 +1062,7 @@ xmlFileWrite (void * context, const char * buffer, int len) {
  * xmlFileClose:
  * @context:  the I/O context
  *
- * Close an I/O channel
+ * DEPRECATED: Internal function, don't use.
  *
  * Returns 0 or -1 in case of error
  */
@@ -2190,11 +2287,12 @@ xmlInputDefaultOpen(xmlParserInputBufferPtr buf, const char *filename) {
 #endif /* LIBXML_ZLIB_ENABLED */
 
     if (xmlFileMatch(filename)) {
-        ret = xmlFileOpenSafe(filename, &buf->context);
+        ret = xmlFdOpen(filename, &buf->context);
 
-        if (buf->context != NULL) {
-            buf->readcallback = xmlFileRead;
-            buf->closecallback = xmlFileClose;
+        /* Note that context can be NULL for stdin */
+        if (ret == XML_ERR_OK) {
+            buf->readcallback = xmlFdRead;
+            buf->closecallback = xmlFdClose;
             return(XML_ERR_OK);
         }
         if (ret != XML_IO_ENOENT)