[openwrt/openwrt] build: preserve profiles.json between builds

[LEDE Commits]

aparcar pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/a463b96241fbc2d142982387eaed9989e201ac7a

commit a463b96241fbc2d142982387eaed9989e201ac7a
Author: Moritz Warning <moritzwarning at web.de>
AuthorDate: Mon Feb 22 00:18:10 2021 +0100

    build: preserve profiles.json between builds
    
    Keep other profiles.json content if the data belongs to the current
    build version.
    
    Also useful for the ImageBuilder, which builds for a single model each
    time. Without this commit the profiles.json would only contain the
    latest build profile information.
    
    Signed-off-by: Moritz Warning <moritzwarning at web.de>
    [improve commit message]
    Signed-off-by: Paul Spooren <mail at aparcar.org>
---
 scripts/json_overview_image_info.py | 32 +++++++++++++++++++++++---------
 1 file changed, 23 insertions(+), 9 deletions(-)

diff --git a/scripts/json_overview_image_info.py b/scripts/json_overview_image_info.py
index 8dbd24af2d..45c05012b1 100755
--- a/scripts/json_overview_image_info.py
+++ b/scripts/json_overview_image_info.py
@@ -18,19 +18,33 @@ work_dir = Path(getenv("WORK_DIR"))
 
 output = {}
 
+
+def get_initial_output(image_info):
+    # preserve existing profiles.json
+    if output_path.is_file():
+        profiles = json.loads(output_path.read_text())
+        if profiles["version_code"] == image_info["version_code"]:
+            return profiles
+    return image_info
+
+
 for json_file in work_dir.glob("*.json"):
     image_info = json.loads(json_file.read_text())
+
     if not output:
-        output.update(image_info)
+        output = get_initial_output(image_info)
+
+    # get first and only profile in json file
+    device_id, profile = next(iter(image_info["profiles"].items()))
+    if device_id not in output["profiles"]:
+        output["profiles"][device_id] = profile
     else:
-        # get first (and only) profile in json file
-        device_id = next(iter(image_info["profiles"].keys()))
-        if device_id not in output["profiles"]:
-            output["profiles"].update(image_info["profiles"])
-        else:
-            output["profiles"][device_id]["images"].append(
-                image_info["profiles"][device_id]["images"][0]
-            )
+        output["profiles"][device_id]["images"].extend(profile["images"])
+
+# make image lists unique by name, keep last/latest
+for device_id, profile in output["profiles"].items():
+    profile["images"] = list({e["name"]: e for e in profile["images"]}.values())
+
 
 if output:
     default_packages, output["arch_packages"] = run(