Additional sanity checks, Removed quote() and quote_free() functions since they can't cleanly handle errors

Signed-off-by: Alex Kent Hajnal <software@alephnull.net>

tdeio/tdeio/job.cpp

@@ -97,10 +97,10 @@ extern "C" {
 
 #ifdef HAVE_ATTR__ATTR_COPY_FILE
 
-//#include <stdio.h>  // For stderr, vsnprintf (already included above)
+//#include <stdio.h>  // For vsnprintf (already included above)
 //#include <errno.h>  // For errno (already included above)
-//#include <stdlib.h> // For free (already included above)
-//#include <string.h> // For strerror, strdup, and strncmp (already implicitly included above)
+//#include <stdlib.h> // For malloc and free (already included above)
+//#include <string.h> // For strerror and strncmp (already implicitly included above)
 #include <stdarg.h> // For va_start and va_end
 
 extern "C" {
@@ -131,61 +131,52 @@ error(struct error_context *ctx, const char *fmt, ...)
   
   va_list ap;
   
-  // Save a copy in case it gets clobbered (shouldn't be needed)
+  // Save a copy since it may get clobbered
   int our_errno = errno;
   
-  // Get length of formatted string (may be 0)
-  va_start(ap, fmt);
-  int len = vsnprintf(nullptr, 0, fmt, ap);
-  va_end(ap);
-  
-  if ( len ) {
-    // There's a prefix string, output it
-    char* buffer = (char*)malloc(len+1);
-    if ( buffer ) {
-      // Buffer allocated, write the error to it
-      va_start(ap, fmt);
-      vsnprintf(&buffer[0], len+1, fmt, ap);
-      va_end(ap);
-      // Write message to log
-      kdDebug(7007) << "Error in attr_copy_file: " << buffer << ": " << strerror(our_errno) << endl;
+  if ( fmt ) {
+    // Format string was supplied
+    
+    // Get length of formatted string (may be 0)
+    va_start(ap, fmt);
+    int len = vsnprintf(nullptr, 0, fmt, ap);
+    va_end(ap);
+    
+    if ( len > 0 ) {
+      // There's a prefix string, output it
+      char* buffer = (char*)malloc(len+1);
+      if ( buffer ) {
+        // Buffer allocated, write the error to it
+        va_start(ap, fmt);
+        int written = vsnprintf(&buffer[0], len+1, fmt, ap);
+        va_end(ap);
+        if ( written > 0 ) {
+          // Write message to log
+          kdDebug(7007) << "Error in attr_copy_file: " << buffer << ": " << strerror(our_errno) << endl;
+        } else {
+          // vsnprintf failed or returned an empty string, just log what we can
+          kdDebug(7007) << "Error in attr_copy_file: " << strerror(our_errno) << endl;
+        }
+      } else {
+        // Buffer allocation failed, just log what we can
+        kdDebug(7007) << "Error in attr_copy_file: " << strerror(our_errno) << endl;
+      }
+      free(buffer);
+      
     } else {
-      // Buffer allocation failed, just log what we can
+      // No prefix string, just log the error code
       kdDebug(7007) << "Error in attr_copy_file: " << strerror(our_errno) << endl;
     }
-    free(buffer);
-    
   } else {
-    // No prefix string, just log the error code
+    // No format string, just log the error code
     kdDebug(7007) << "Error in attr_copy_file: " << strerror(our_errno) << endl;
   }
 }
 
-/*
- * Optional handler for quoting path names in error messages.
- * (This is a very stupid example!)
- */
-static const char *
-quote(struct error_context *ctx, const char *pathname)
-{
-  char *pn = strdup(pathname), *p;
-  pathname = strdup(pathname);
-  for (p = pn; *p != '\0'; p++)
-    if (*p & 0x80)
-      *p='?';
-  return pn;
-}
-
-static void
-quote_free(struct error_context *ctx, const char *name)
-{
-  free((void *)name);
-}
-
 /*
  * The error context we pass to attr_copy_file().
  */
-struct error_context ctx = { error, quote, quote_free };
+struct error_context ctx = { error, NULL, NULL };
 
 /*
  * Optional attribute filter for attr_copy_file(). This example 
@@ -205,7 +196,14 @@ static int is_user_attr(const char *name, struct error_context *ctx)
   // Note that non-Linux systems (including Solaris and Darwin/OSX) may 
   // use a different naming scheme for user attributes.  AFAIK FreeBSD 
   // and NetBSD do support the "user" namespace.
-  return strncmp(name, "user.", 5) == 0;
+  
+  if ( name ) {
+    // Name is not a null pointer
+    return strncmp(name, "user.", 5) == 0;
+  } else {
+    // Name is a null pointer
+    return -1; // Not matched
+  }
   
   // If this function is not specified in the call to attr_copy_file then the 
   // default behavior is to use the following heuristic instead (see above):