fix(ScanResultsStorage): Correct debug log output about mismatches

Previously, the empty `scanResults` were used in log output. Refactor
code to avoid that error.

Signed-off-by: Sebastian Schuberth <[email protected]>

Author: sschuberth

scanner/src/main/kotlin/ScanResultsStorage.kt

@@ -154,27 +154,30 @@ abstract class ScanResultsStorage : PackageBasedScanStorage {
             if (results.isEmpty()) {
                 results
             } else {
-                val scanResults = results.toMutableList()
+                val (matchingProvenance, nonMatchingProvenance) = results.partition { it.provenance.matches(pkg) }
 
-                // Only keep scan results whose provenance information matches the package information.
-                scanResults.retainAll { it.provenance.matches(pkg) }
-                if (scanResults.isEmpty()) {
+                if (matchingProvenance.isEmpty()) {
                     logger.debug {
                         "No stored scan results found for $pkg. The following entries with non-matching provenance " +
-                            "have been ignored: ${scanResults.map { it.provenance }}"
+                            "have been ignored: ${nonMatchingProvenance.map { it.provenance }}"
                     }
+
+                    matchingProvenance
                 } else {
-                    // Only keep scan results from compatible scanners.
-                    scanResults.retainAll { scannerCriteria.matches(it.scanner) }
-                    if (scanResults.isEmpty()) {
+                    val (matchingCriteria, nonMatchingCriteria) = matchingProvenance.partition {
+                        scannerCriteria.matches(it.scanner)
+                    }
+
+                    if (matchingCriteria.isEmpty()) {
                         logger.debug {
-                            "No stored scan results found for $scannerCriteria. The following entries with " +
-                                "incompatible scanners have been ignored: ${scanResults.map { it.scanner }}"
+                            "No stored scan results for '${pkg.id.toCoordinates()}' match $scannerCriteria. The " +
+                                "following entries with non-matching criteria have been ignored: " +
+                                nonMatchingCriteria.map { it.scanner }
                         }
                     }
-                }
 
-                scanResults
+                    matchingCriteria
+                }
             }
         }