Alas. Fix #pragma magic for GCC <= 4.5.

push/pop was introduced for GCC4.6 only - so avoid it.
Also, properly fix the fgets warning.

simgear/math/SGSphere.hxx

@@ -25,7 +25,6 @@ public:
 
 #ifdef __GNUC__
 // Avoid "_center not initialized" warnings.
-#   pragma GCC diagnostic push
 #   pragma GCC diagnostic ignored "-Wuninitialized"
 #endif
 
@@ -49,7 +48,7 @@ public:
 
 #ifdef __GNUC__
   // Restore warning settings.
-#   pragma GCC diagnostic pop
+#   pragma GCC diagnostic warning "-Wuninitialized"
 #endif
 
   const SGVec3<T>& getCenter() const

simgear/math/SGVec3.hxx

@@ -31,7 +31,6 @@ public:
 
 #ifdef __GNUC__
 // Avoid "_data not initialized" warnings (see comment below).
-#   pragma GCC diagnostic push
 #   pragma GCC diagnostic ignored "-Wuninitialized"
 #endif
 
@@ -50,7 +49,7 @@ public:
 
 #ifdef __GNUC__
   // Restore warning settings.
-#   pragma GCC diagnostic pop
+#   pragma GCC diagnostic warning "-Wuninitialized"
 #endif
 
   /// Constructor. Initialize by the given values

simgear/timing/timezone.cxx

@@ -143,7 +143,8 @@ SGTimeZoneContainer::SGTimeZoneContainer(const char *filename)
     errno = 0;
 
     while (1) {
-        (void) fgets(buffer, 256, infile);
+        if (0 == fgets(buffer, 256, infile))
+            break;
         if (feof(infile)) {
             break;
         }