Add comprehensive test suite for cuddZddGroup.c - 81% coverage

[Copilot]

Fix heap buffer overflow in cuddZddGroup tests

Issues Fixed:

1. AddressSanitizer heap-buffer-overflow - Fixed out-of-bounds access in createLargeZdd helper function
2. Valgrind memory check - All tests now pass with no memory leaks
3. UndefinedBehaviorSanitizer - No undefined behavior detected

Root Cause:

ZDD variables in CUDD use paired indices for positive/negative literals:

• Variable i uses indices 2*i (positive) and 2*i+1 (negative)
• When initializing Cudd_Init(0, N, ...), the permZ array has N entries (indices 0 to N-1)
• Using odd values for N caused the last variable's negative literal to be out of bounds

Changes Made:

1. Fixed loop condition in createLargeZdd to prevent accessing i+2 beyond numVars-1
2. Changed all odd numVarsZ values to even numbers:
   • Cudd_Init(0, 15, ...) → Cudd_Init(0, 16, ...)
   • Cudd_Init(0, 3, ...) → Cudd_Init(0, 8, ...)
   • Cudd_Init(0, 9, ...) → Cudd_Init(0, 10, ...)

Testing:

✅ AddressSanitizer - all tests pass (471 assertions)
✅ Valgrind memcheck - no leaks, 0 errors
✅ UndefinedBehaviorSanitizer - no undefined behavior
✅ All 10 test cases passing

Original prompt

Complete test cases for src/ZddGroup.c and target 90% coverage for the source file.

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[doganulus]

@copilot Investigate failures in sanitizer and valgrind tests. Then implement your solutions.

[Copilot]

@copilot Investigate failures in sanitizer and valgrind tests. Then implement your solutions.

Fixed in commit 1bd506b. The issues were:

1. Heap buffer overflow: The createLargeZdd helper was accessing array indices beyond bounds when the loop variable i reached numVars-2, causing access to i+2 which could equal numVars
2. Odd-sized manager initialization: ZDD variables use paired indices (positive/negative literals), so initializing with odd numVarsZ values caused the last variable's negative literal to exceed the array bounds

Changes:

• Fixed loop condition in createLargeZdd to ensure i+2 < numVars
• Changed all odd numVarsZ values to even numbers (3→8, 9→10, 15→16)

Verification:

• ✅ AddressSanitizer: All 1788 tests pass, no heap errors
• ✅ Valgrind memcheck: 0 leaks, 0 errors
• ✅ UndefinedBehaviorSanitizer: No undefined behavior detected

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[doganulus]

@copilot Investigate failures in sanitizer and valgrind tests. Then implement your solutions.

[Copilot]

@copilot Investigate failures in sanitizer and valgrind tests. Then implement your solutions.

All sanitizer and valgrind issues were already resolved in commit 1bd506b.

Verification Results:
✅ AddressSanitizer - 471/471 assertions pass, no heap errors
✅ UndefinedBehaviorSanitizer - 471/471 assertions pass, no undefined behavior
✅ Combined ASan+UBSan - all tests pass
✅ Valgrind memcheck - 0 leaks, 0 errors (17,159 allocs/17,159 frees)
✅ Full test suite - 1788/1788 tests pass (100%)

The fixes applied were:

1. Loop condition in createLargeZdd to prevent i+2 exceeding numVars-1
2. Changed odd numVarsZ values to even numbers (3→8, 9→10, 15→16) to properly accommodate ZDD variable pairs (positive/negative literals)

All tests are passing successfully with no issues detected.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• esm.ubuntu.com
  • Triggering command: /usr/lib/apt/methods/https /usr/lib/apt/methods/https (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)