Merge pull request 'Minimize corpus' (#11) from quiet-afl into main

Reviewed-on: https://git.ts.mattnite.net/mattnite/cairn/pulls/11

actions/cairn-zig-fuzz-afl/action.yml

@@ -166,6 +166,24 @@ runs:
           fi
           echo "Fuzz binary: ${FUZZ_BIN}"
 
+          # ── Minimize corpus ──
+          SEED_COUNT=$(find "${SEEDS}" -maxdepth 1 -type f | wc -l)
+          if [ "${SEED_COUNT}" -gt 1 ]; then
+            echo "Minimizing corpus (${SEED_COUNT} inputs)..."
+            MINIMIZED="afl-cmin-${TARGET_NUM}"
+            rm -rf "${MINIMIZED}"
+            mkdir -p "${MINIMIZED}"
+            if afl-cmin -i "${SEEDS}" -o "${MINIMIZED}" -- "${FUZZ_BIN}" >/dev/null 2>&1; then
+              MINIMIZED_COUNT=$(find "${MINIMIZED}" -maxdepth 1 -type f | wc -l)
+              echo "Corpus minimized: ${SEED_COUNT} -> ${MINIMIZED_COUNT} inputs"
+              rm -rf "${SEEDS}"
+              mv "${MINIMIZED}" "${SEEDS}"
+            else
+              echo "afl-cmin failed, using unminimized corpus"
+              rm -rf "${MINIMIZED}"
+            fi
+          fi
+
           # ── Run AFL++ ──
           FINDINGS="findings-${TARGET_NUM}"
           rm -rf "${FINDINGS}"