Fix integer divide-by-zero in script.c's post-suite histogram printer.

uMax (the largest histogram bucket count) can be 0 when a script run's
positions are all unsolved -- ASSERT(uMax > 0) doesn't stop this in a
non-DEBUG build, and the following loop unconditionally divides by
uMax, crashing with SIGFPE. Hit repeatedly today running single-position
diagnostic scripts (an isolated unsolved position naturally has an
all-zero histogram) while investigating an LMR regression on ECM.213.

Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01YGSMkwjqiCk4XhbfN7ugD2

1 files changed, 5 insertions, 6 deletions

diff --git a/src/script.c b/src/script.c
index 085f9ec..142b42c 100755
--- a/src/script.c
+++ b/src/script.c
@@ -479,14 +479,13 @@ Return value:
                     uMax = g_SuiteCounters.uHistogram[u];
                 }
             }
-            ASSERT(uMax > 0);
-            for (u = 0; u < SUITE_NUM_HISTOGRAM; u++) 
+            for (u = 0; u < SUITE_NUM_HISTOGRAM; u++)
             {
-                Trace("%4.1f .. %4.1f: ", 
+                Trace("%4.1f .. %4.1f: ",
                       (double)u * dMult, (double)(u + 1) * dMult);
-                for (v = 0; 
-                     v < 50 * g_SuiteCounters.uHistogram[u] / uMax; 
-                     v++) 
+                for (v = 0;
+                     (uMax > 0) && (v < 50 * g_SuiteCounters.uHistogram[u] / uMax);
+                     v++)
                 {
                     Trace("*");
                 }