Be a bit safer with signed arithmetic, thus quieting some signed-over…

…flow warnings from GCC (HDFGroup#1706)

* Avoid a signed overflow: check the range of `entry_ptr->age` before
increasing it instead of increasing it and then checking the range.
This quiets a GCC warning.

* Avoid the potential for signed overflow by rewriting expressions
`MAX(0, fwidth - n)` as `MAX(n, fwidth) - n` for various `n`.
This change quiets some GCC warnings.

* Change some local variables that cannot take sensible negative values
from signed to unsigned.  This quiets GCC warnings about potential
signed overflow.

* In a handful of instances, check the range of a signed integer before
increasing/decreasing it, just in case the increase/decrease overflows.
This quiets a handful of GCC signed-overflow warnings.

* Committing clang-format changes

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

src/H5Bdbg.c

@@ -110,20 +110,20 @@ H5B_debug(H5F_t *f, haddr_t addr, FILE *stream, int indent, int fwidth, const H5
      */
     for (u = 0; u < bt->nchildren; u++) {
         HDfprintf(stream, "%*sChild %d...\n", indent, "", u);
-        HDfprintf(stream, "%*s%-*s %" PRIuHADDR "\n", indent + 3, "", MAX(0, fwidth - 3),
+        HDfprintf(stream, "%*s%-*s %" PRIuHADDR "\n", indent + 3, "", MAX(3, fwidth) - 3,
                   "Address:", bt->child[u]);
 
         /* If there is a key debugging routine, use it to display the left & right keys */
         if (type->debug_key) {
             /* Decode the 'left' key & print it */
-            HDfprintf(stream, "%*s%-*s\n", indent + 3, "", MAX(0, fwidth - 3), "Left Key:");
+            HDfprintf(stream, "%*s%-*s\n", indent + 3, "", MAX(3, fwidth) - 3, "Left Key:");
             HDassert(H5B_NKEY(bt, shared, u));
-            (void)(type->debug_key)(stream, indent + 6, MAX(0, fwidth - 6), H5B_NKEY(bt, shared, u), udata);
+            (void)(type->debug_key)(stream, indent + 6, MAX(6, fwidth) - 6, H5B_NKEY(bt, shared, u), udata);
 
             /* Decode the 'right' key & print it */
-            HDfprintf(stream, "%*s%-*s\n", indent + 3, "", MAX(0, fwidth - 3), "Right Key:");
+            HDfprintf(stream, "%*s%-*s\n", indent + 3, "", MAX(3, fwidth) - 3, "Right Key:");
             HDassert(H5B_NKEY(bt, shared, u + 1));
-            (void)(type->debug_key)(stream, indent + 6, MAX(0, fwidth - 6), H5B_NKEY(bt, shared, u + 1),
+            (void)(type->debug_key)(stream, indent + 6, MAX(6, fwidth) - 6, H5B_NKEY(bt, shared, u + 1),
                                     udata);
         } /* end if */
     }     /* end for */

src/H5Cimage.c

@@ -2737,10 +2737,11 @@ H5C__prep_for_file_close__setup_image_entries_array(H5C_t *cache_ptr)
              */
             if (entry_ptr->type->id == H5AC_PREFETCHED_ENTRY_ID) {
                 image_entries[u].type_id = entry_ptr->prefetch_type_id;
-                image_entries[u].age     = entry_ptr->age + 1;
 
-                if (image_entries[u].age > H5AC__CACHE_IMAGE__ENTRY_AGEOUT__MAX)
+                if (entry_ptr->age >= H5AC__CACHE_IMAGE__ENTRY_AGEOUT__MAX)
                     image_entries[u].age = H5AC__CACHE_IMAGE__ENTRY_AGEOUT__MAX;
+                else
+                    image_entries[u].age = entry_ptr->age + 1;
             } /* end if */
             else {
                 image_entries[u].type_id = entry_ptr->type->id;