ReadPage() must've been returning int at some point. It is returning
FPXStatus for, at least, 5 years now, but gcc never warned about us
checking invalid values. Thanks to clang for finding this redundancy.
--- fpx/fpxlib.cpp	2007-11-02 03:10:05.000000000 -0400
+++ fpx/fpxlib.cpp	2012-10-04 22:49:40.000000000 -0400
@@ -825,5 +825,5 @@
               FPXImageDesc* renderingBuffer)
 {
-  FPXStatus status = FPX_OK;
+  FPXStatus status;
   if (!thePage)
     status = FPX_INVALID_FPX_HANDLE;
@@ -839,18 +839,7 @@
     else {
       GtheSystemToolkit->SetUsedColorSpace(image.GetBaselineColorSpace());
-      switch (thePage->ReadPage (image.Get32BitsBuffer())) {
-        case -2 :
-          status = FPX_FILE_READ_ERROR;
-          break;
-        case -3 :
-          status = FPX_LOW_MEMORY_ERROR;
-          break;
-        case 0:
-          image.UpdateDescriptor();
-          break;
-      default:
-        {
-        }
-      }
+      status = thePage->ReadPage(image.Get32BitsBuffer());
+      if (status == FPX_OK)
+        image.UpdateDescriptor();
     }
   }
@@ -863,5 +852,5 @@
               FPXImageDesc* renderingBuffer)
 {
-  FPXStatus status = FPX_OK;
+  FPXStatus status;
   if (!thePage)
     status = FPX_INVALID_FPX_HANDLE;
@@ -877,18 +866,7 @@
     else {
       GtheSystemToolkit->SetUsedColorSpace(line.GetBaselineColorSpace());
-      switch (thePage->ReadPageLine (lineNumber, line.Get32BitsBuffer())) {
-        case -2 :
-          status = FPX_FILE_READ_ERROR;
-          break;
-        case -3 :
-          status = FPX_LOW_MEMORY_ERROR;
-          break;
-        case 0:
-          line.UpdateDescriptor();
-          break;
-      default:
-        {
-        }
-      }
+      status = thePage->ReadPageLine (lineNumber, line.Get32BitsBuffer());
+      if (status == FPX_OK)
+        line.UpdateDescriptor();
     }
   }