Remove version-check for relnum in H5check. (#812)

* Remove version-check for relnum in H5check.

* Add in release exception code check

* Fix typos

* Fix more typos

* Rework comments

* format change

* format whitespace

* Library version must be less than or equal to headers

* Need the NOT version of the compare

* Enable release+1 check for PASS

* Add release note

* Update note

1 files changed, 19 insertions, 0 deletions

diff --git a/release_docs/RELEASE.txt b/release_docs/RELEASE.txt
index bd186d8..314a713 100644
--- a/release_docs/RELEASE.txt
+++ b/release_docs/RELEASE.txt
@@ -463,6 +463,25 @@ New Features
 
     Library:
     --------
+    - Change how the release part of version, in major.minor.release is checked
+      for compatibility
+
+      The HDF5 library uses a function, H5check_version, to check that
+      the version defined in the header files, which is used to compile an
+      application is compatible with the version codified in the library, which
+      the application loads at runtime. This previously required an exact match
+      or the library would print a warning, dump the build settings and then
+      abort or continue. An environment variable controlled the logic.
+
+      Now the function first checks that the library release version, in
+      major.minor.release, is not older than the version in the headers.
+      Secondly, if the release version is different, it checks if either
+      the library version or the header version is in the exception list, in
+      which case the release part of version, in major.minor.release, must
+      be exact. An environment variable still controls the logic.
+
+        (ADB - 2021/07/27)
+
     - gcc warning suppression macros were moved out of H5public.h
 
       The HDF5 library uses a set of macros to suppress warnings on gcc.