From c31b7a8f6f0a300c927a79d687c8f3d335340bc8 Mon Sep 17 00:00:00 2001
From: Evan Nemerson <evan@nemerson.com>
Date: Thu, 30 Mar 2017 10:43:22 -0700
Subject: [PATCH 1/2] Handle rand_int_range with min == max without dividing by
 0

https://github.com/nemequ/munit/issues/30
---
 munit.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/munit.c b/munit.c
index 00ede07..f051ab8 100644
--- a/munit.c
+++ b/munit.c
@@ -998,11 +998,15 @@ munit_rand_at_most(munit_uint32_t salt, munit_uint32_t max) {
 
 int
 munit_rand_int_range(int min, int max) {
-  munit_uint64_t range = (munit_uint64_t) max - (munit_uint64_t) min;
+  munit_uint64_t range;
 
-  if (min > max)
+  if (min == max)
+    return min;
+  else if (min > max)
     return munit_rand_int_range(max, min);
 
+  range = (munit_uint64_t) max - (munit_uint64_t) min;
+
   if (range > (~((munit_uint32_t) 0U)))
     range = (~((munit_uint32_t) 0U));
 

From 389e5e23b0d5532460c9f33f2bceeb7752994a0c Mon Sep 17 00:00:00 2001
From: Sye van der Veen <syeberman@gmail.com>
Date: Sat, 30 Nov 2024 18:12:03 -0500
Subject: [PATCH 2/2] Avoid divide-by-zero in munit_rand_state_at_most when max
 is zero

---
 munit.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/munit.c b/munit.c
index f051ab8..f258333 100644
--- a/munit.c
+++ b/munit.c
@@ -962,6 +962,7 @@ munit_rand_memory(size_t size, munit_uint8_t data[MUNIT_ARRAY_PARAM(size)]) {
   } while (!munit_atomic_cas(&munit_rand_state, &old, state));
 }
 
+/* max cannot be zero. */
 static munit_uint32_t
 munit_rand_state_at_most(munit_uint32_t* state, munit_uint32_t salt, munit_uint32_t max) {
   /* We want (UINT32_MAX + 1) % max, which in unsigned arithmetic is the same
@@ -983,6 +984,7 @@ munit_rand_state_at_most(munit_uint32_t* state, munit_uint32_t salt, munit_uint3
   return x % max;
 }
 
+/* max cannot be zero. */
 static munit_uint32_t
 munit_rand_at_most(munit_uint32_t salt, munit_uint32_t max) {
   munit_uint32_t old, state;
@@ -1618,7 +1620,10 @@ munit_test_runner_run_test(MunitTestRunner* runner,
          * running a single test, but we don't want every test with
          * the same number of parameters to choose the same parameter
          * number, so use the test name as a primitive salt. */
-        pidx = munit_rand_at_most(munit_str_hash(test_name), possible - 1);
+        if (possible > 1)
+          pidx = munit_rand_at_most(munit_str_hash(test_name), possible - 1);
+        else
+          pidx = 0;
         if (MUNIT_UNLIKELY(munit_parameters_add(&params_l, &params, pe->name, pe->values[pidx]) != MUNIT_OK))
           goto cleanup;
       } else {