io: Fix return value of xmlFileRead

This broke in commit 6d27c54.

Fixes #766.

Author: nwellnhof

CMakeLists.txt

@@ -528,7 +528,7 @@ if(LIBXML2_WITH_TESTS)
     endif()
     add_test(NAME testchar COMMAND testchar)
     add_test(NAME testdict COMMAND testdict)
-    add_test(NAME testparser COMMAND testparser)
+    add_test(NAME testparser COMMAND testparser WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
     add_test(NAME testrecurse COMMAND testrecurse WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
     add_test(NAME testThreads COMMAND testThreads WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
 endif()

testparser.c

@@ -4,6 +4,8 @@
  * See Copyright for the status of this software.
  */
 
+#define XML_DEPRECATED
+
 #include <libxml/parser.h>
 #include <libxml/uri.h>
 #include <libxml/xmlreader.h>
@@ -95,6 +97,34 @@ testNodeGetContent(void) {
     return err;
 }
 
+static int
+testCFileIO(void) {
+    xmlDocPtr doc;
+    int err = 0;
+
+    /* Deprecated FILE-based API */
+    xmlRegisterInputCallbacks(xmlFileMatch, xmlFileOpen, xmlFileRead,
+                              xmlFileClose);
+    doc = xmlReadFile("test/ent1", NULL, 0);
+
+    if (doc == NULL) {
+        err = 1;
+    } else {
+        xmlNodePtr root = xmlDocGetRootElement(doc);
+
+        if (root == NULL || !xmlStrEqual(root->name, BAD_CAST "EXAMPLE"))
+            err = 1;
+    }
+
+    xmlFreeDoc(doc);
+    xmlPopInputCallbacks();
+
+    if (err)
+        fprintf(stderr, "xmlReadFile failed with FILE input callbacks\n");
+
+    return err;
+}
+
 #ifdef LIBXML_SAX1_ENABLED
 static int
 testBalancedChunk(void) {
@@ -540,6 +570,7 @@ main(void) {
     err |= testStandaloneWithEncoding();
     err |= testUnsupportedEncoding();
     err |= testNodeGetContent();
+    err |= testCFileIO();
 #ifdef LIBXML_SAX1_ENABLED
     err |= testBalancedChunk();
 #endif

xmlIO.c

@@ -776,7 +776,7 @@ xmlFileRead(void * context, char * buffer, int len) {
     if ((bytes < (size_t) len) && (ferror(file)))
         return(-xmlIOErr(0, "fread()"));
 
-    return(len);
+    return(bytes);
 }
 
 #ifdef LIBXML_OUTPUT_ENABLED