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MASK = 1023  # 10bit
KEYS = [0x123, 0x456, 0x789, 0xABC]

def F(r, k):
    return ((r * 1103515245 + k) & MASK)

def secure_perfect_hash(x: int) -> int:
    if not (0 <= x <= 999_999):
        raise ValueError("out of range")

    L = (x >> 10) & MASK
    R = x & MASK

    for k in KEYS:
        L, R = R, L ^ F(R, k)

    return (L << 10) | R

def to_base36(n):
    chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    s = ""
    while n:
        n, r = divmod(n, 36)
        s = chars[r] + s
    return s.zfill(6)

diff --git a/support/dfa.c b/support/dfa.c
index 74ec0008..0bfd8048 100644
--- a/support/dfa.c
+++ b/support/dfa.c
@@ -406,8 +406,9 @@ struct mb_char_classes
 {
   ptrdiff_t cset;
   bool invert;
-  char32_t *chars;              /* Normal characters.  */
   idx_t nchars;
+  char32_t *chars               /* Normal characters.  */
+    _GL_ATTRIBUTE_COUNTED_BY (nchars);
   idx_t nchars_alloc;
 };

diff --git a/support/ChangeLog b/support/ChangeLog
index 2c88ae4f..a807e6ac 100644
--- a/support/ChangeLog
+++ b/support/ChangeLog
@@ -1,3 +1,8 @@
+2026-05-03         Arnold D. Robbins     <arnold@skeeve.com>
+
+	* pam.c (integrity_check): Cast `nrev' to void. Simpler way to
+	silence the warning, and it actually works.
+
 2026-05-01         Arnold D. Robbins     <arnold@skeeve.com>

diff --git a/support/pma.c b/support/pma.c
index 75f084ea..29a9def0 100644
--- a/support/pma.c
+++ b/support/pma.c
@@ -231,9 +231,8 @@ static int integrity_check(int line) {  // can be slow; intended for debugging s
       for (p = f->fnext; p != f; p = p->fnext) { nfwd++; assert(VAF(p)); assert(0 == getbit(p, IU)); }
       for (p = f->fprev; p != f; p = p->fprev) { nrev++; assert(VAF(p)); assert(0 == getbit(p, IU)); }
       assert(nfwd == nrev);    // count should be the same in both directions
-      // the following line uses nrev to silence a stupid gcc 16.1 warning.
-      if (nfwd != nrev) fprintf(stderr, "%s:%d: shouldn't happen\n",
-		      __FILE__, __LINE__);
+      // the following line silences a stupid gcc 16.1 warning.
+      (void) nrev;
       tf += nfwd;
       // check ao sizes against UB
       for (p = f->fnext; p != f; p = p->fnext) {

diff --git a/gettext-runtime/src/envsubst.c b/gettext-runtime/src/envsubst.c
index db7693510..4ff05d9d5 100644
--- a/gettext-runtime/src/envsubst.c
+++ b/gettext-runtime/src/envsubst.c
@@ -308,8 +308,9 @@ print_variables (const char *string)
 typedef struct string_list_ty string_list_ty;
 struct string_list_ty
 {
-  const char **item;
   size_t nitems;
+  const char **item
+    COUNTED_BY (nitems);
   size_t nitems_max;
 };