Convert assertion on (possibly corrupt) file contents to normal error…

… check (HDFGroup#1861)

* Convert assertion on (possibly corrupt) file contents to normal error check

* Committing clang-format changes

Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

release_docs/RELEASE.txt

@@ -170,7 +170,16 @@ Bug Fixes since HDF5-1.12.1 release
 ===================================
     Library
     -------
-    -
+    - Converted an assertion on (possibly corrupt) file contents to a normal
+      error check
+
+      Previously, the library contained an assertion check that a read superblock
+      doesn't contain a superblock extension message when the superblock
+      version < 2. When a corrupt HDF5 file is read, this assertion can be triggered
+      in debug builds of HDF5. In production builds, this situation could cause
+      either a library error or a crash, depending on the platform.
+
+      (JTH - 2022/07/08, HDFFV-11316, HDFFV-11317)
 
 
     Java Library

src/H5Fsuper.c

@@ -686,7 +686,9 @@ H5F__super_read(H5F_t *f, H5P_genplist_t *fa_plist, hbool_t initial_read)
         /* Sanity check - superblock extension should only be defined for
          *      superblock version >= 2.
          */
-        HDassert(sblock->super_vers >= HDF5_SUPERBLOCK_VERSION_2);
+        if (sblock->super_vers < HDF5_SUPERBLOCK_VERSION_2)
+            HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL,
+                        "invalid superblock - extension message should not be defined for version < 2")
 
         /* Check for superblock extension being located "outside" the stored
          *      'eoa' value, which can occur with the split/multi VFD.