rbuscli: fix coverity RESOURCE_LEAK in discovery commands

[svc-rdkeportal01]

Fix Coverity RESOURCE_LEAK in Discovery Commands

Coverity Issues Fixed

This PR fixes three related Coverity RESOURCE_LEAK defects in utils/rbuscli/rbuscli.c:

• Coverity CID 112 (line 1004): execute_discover_component_cmd
• Coverity CID 113 (line 1093): execute_discover_wildcard_dests_cmd
• Coverity CID 114 (line 1049): execute_discover_elements_cmd

Note: These are Coverity defect IDs, not GitHub issue numbers.

Root Cause

All three functions had similar resource leak patterns:

1. CID 112: Memory allocated by rbus_discoverComponentName() was not freed in the error path
2. CID 113: Uninitialized destinations pointer + no cleanup when rbus_discoverWildcardDestinations() fails
3. CID 114: Memory potentially allocated by rbus_discoverComponentDataElements() even when numElements == 0, not freed in error path

Changes Made

For each function, the fix includes:

1. Initialize pointers to NULL to prevent undefined behavior

   char **pComponentNames = NULL;
   char **pElementNames = NULL;
   char **destinations = NULL;

2. Add cleanup in error paths to prevent memory leaks

   free(pointer);

3. Add return statements to prevent fall-through to unintended code paths

---

Coverity Defect Details:

• CID 112: Line 1004 in utils/rbuscli/rbuscli.c, function execute_discover_component_cmd()
• CID 113: Line 1093 in utils/rbuscli/rbuscli.c, function execute_discover_wildcard_dests_cmd()
• CID 114: Line 1049 in utils/rbuscli/rbuscli.c, function execute_discover_elements_cmd()

Coverity Checker: RESOURCE_LEAK

[Copilot]

Pull request overview

This PR fixes three Coverity RESOURCE_LEAK defects in the rbuscli tool by adding proper cleanup in error paths for discovery command functions. The changes add pointer initialization to NULL and cleanup code when RBUS discovery API calls fail, preventing potential memory leaks.

Key changes:

• Initialize pointer variables to NULL to prevent undefined behavior in error paths
• Add memory cleanup in error paths for three discovery functions
• Add explicit return statements after error handling to prevent fall-through

---

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[Copilot]

[nitpick] The NULL check before free() is unnecessary and inconsistent with the rest of the codebase. In C, free(NULL) is well-defined and safe. The rest of this file calls free() directly without NULL checks (e.g., lines 953, 955, 991, 993, 1041, 1043, 1090, 1092).

Consider simplifying to:

free(destinations);

Suggested change

	if (destinations != NULL)
	{
	free(destinations);
	}
	free(destinations);

[Copilot]

[nitpick] The NULL check before free() is unnecessary and inconsistent with the rest of the codebase. In C, free(NULL) is well-defined and safe. The rest of this file calls free() directly without NULL checks (e.g., lines 953, 955, 991, 993, 1041, 1043, 1090, 1092).

Consider simplifying to:

free(pComponentNames);

Suggested change

	if (pComponentNames != NULL)
	{
	free(pComponentNames);
	}
	free(pComponentNames);

[Copilot]

[nitpick] The NULL check before free() is unnecessary and inconsistent with the rest of the codebase. In C, free(NULL) is well-defined and safe. The rest of this file calls free() directly without NULL checks (e.g., lines 953, 955, 991, 993, 1041, 1043, 1090, 1092).

Consider simplifying to:

free(pElementNames);

Suggested change

	if (pElementNames != NULL)
	{
	free(pElementNames);
	}
	free(pElementNames);

[svc-rdkeportal01]

Response to Copilot Review

Thank you @copilot-pull-request-reviewer for the excellent feedback! 🙏

Changes Made

I've addressed all 3 nitpick comments by removing the unnecessary NULL checks before free().

You're absolutely right:

• ✅ free(NULL) is well-defined and safe in C standard
• ✅ The rest of rbuscli.c calls free() directly (lines 953, 955, 991, 993, 1041, 1043, 1090, 1092)
• ✅ Our NULL checks were inconsistent with codebase style

Changes:

// Before (5 lines):
if (pComponentNames != NULL)
{
    free(pComponentNames);
}

// After (1 line):
free(pComponentNames);

Applied to all 3 functions:

• execute_discover_component_cmd (line 1003)
• execute_discover_elements_cmd (line 1050)
• execute_discover_wildcard_dests_cmd (line 1102)

Result:

• ✅ Simpler code (removed 12 lines)
• ✅ Consistent with codebase style
• ✅ Same safety guarantees

The fix now matches the coding style of the rest of the file. Ready for re-review!

[Copilot]

@svc-rdkeportal01 I've opened a new pull request, #402, to work on those changes. Once the pull request is ready, I'll request review from you.