bug(sbom): Trivy overwrites Applications when multiple sbom files contain aggregated language type

[DmitriyLewen]

Description

We already had similar case - when single sbom file contains multiple Applications for same aggregated language type (see #5812).
This problem has been fixed.

But we have similar behavior when image contains multiple sbom files for same aggregated type (e.g. Java, Python, etc)

FilePath for these Applications is empty:

trivy/pkg/sbom/io/decode.go

Lines 179 to 183 in 88ba460

	// Aggregation Types use the name of the language (e.g. `Java`, `Python`, etc.) as the component name.
	// Other language files use the file path as their name.
	if !slices.Contains(ftypes.AggregatingTypes, app.Type) {
	app.FilePath = c.Name
	}

So when we fill nestedMap in ApplyLayers function - we overwrite Applications:

trivy/pkg/fanal/applier/docker.go

Lines 121 to 125 in 69bf7e0

	// Apply language-specific packages
	for _, app := range layer.Applications {
	key := fmt.Sprintf("%s/type:%s", app.FilePath, app.Type)
	nestedMap.SetByString(key, sep, app)
	}

Example:

➜ tree
.
├── Dockerfile
├── api
│   └── log4j-api-2.24.1.jar
└── core
    └── log4j-core-2.24.1.jar

3 directories, 3 files
➜ trivy -q rootfs ./api -f spdx-json -o report-api.spdx.json    
➜ trivy -q rootfs ./core -f spdx-json -o report-core.spdx.json

➜ cat Dockerfile 
FROM alpine

COPY ./report-api.spdx.json /api/report-api.spdx.json

COPY ./report-core.spdx.json /core/report-core.spdx.json
                       
➜ docker build -t test:7846 .
[+] Building 0.1s (8/8) FINISHED                           docker:desktop-linux
...

➜  example trivy -q image test:7846 -f json --list-all-pkgs --pkg-types library
{
...
  "Results": [
    {
      "Target": "Java",
      "Class": "lang-pkgs",
      "Type": "jar",
      "Packages": [
        {
          "ID": "org.apache.logging.log4j:log4j-core:2.24.1",
          "Name": "org.apache.logging.log4j:log4j-core",
          "Identifier": {
            "PURL": "pkg:maven/org.apache.logging.log4j/[email protected]",
            "UID": "ea631ef0af9d09d6"
          },
          "Version": "2.24.1",
          "Licenses": [
            "NOASSERTION"
          ],
          "Layer": {
            "DiffID": "sha256:efe02b781f0ce0882531fe6ae24f5e369dcd59a33cefac6d9c184e1937298507"
          },
          "FilePath": "log4j-core-2.24.1.jar"
        }
      ]
    }
  ]
}

Discussed in #7846