simplify fuzzer branch handling

Author: strtgbb

docker/test/fuzzer/run-fuzzer.sh

@@ -42,32 +42,25 @@ function clone
     (
         cd "$repo_dir"
         if [ "$PR_TO_TEST" != "0" ]; then
-            if git fetch --depth 100 origin "+refs/pull/$PR_TO_TEST/merge"; then
+            if git fetch --depth 1 origin "+refs/pull/$PR_TO_TEST/merge"; then
                 git checkout FETCH_HEAD
                 echo "Checked out pull/$PR_TO_TEST/merge ($(git rev-parse FETCH_HEAD))"
             else
-                git fetch --depth 100 origin "+refs/pull/$PR_TO_TEST/head"
+                git fetch --depth 1 origin "+refs/pull/$PR_TO_TEST/head"
                 git checkout "$SHA_TO_TEST"
                 echo "Checked out nominal SHA $SHA_TO_TEST for PR $PR_TO_TEST"
             fi
             # Use BASE_BRANCH from environment variable if available, otherwise fall back to master
             if [ -n "$BASE_BRANCH" ]; then
                 echo "Using base branch from environment: $BASE_BRANCH"
-                # Fetch the specific base branch first (without depth limit to allow merge-base)
-                git fetch origin --depth 100 "$BASE_BRANCH" || {
+                # Fetch the specific base branch first
+                git fetch --depth 1 origin "$BASE_BRANCH" || {
                     echo "ERROR: Could not fetch base branch: $BASE_BRANCH"
                     echo "Available remote branches:"
                     git branch -r
                     exit 1
                 }
-                MERGE_BASE=$(git merge-base HEAD "origin/$BASE_BRANCH" 2>/dev/null || echo "")
-                if [ -z "$MERGE_BASE" ]; then
-                    echo "ERROR: No merge base found with base branch: $BASE_BRANCH"
-                    echo "Available remote branches:"
-                    git branch -r
-                    exit 1
-                fi
-                git diff --name-only "$MERGE_BASE" HEAD | tee ci-changed-files.txt
+                git diff --name-only "origin/$BASE_BRANCH" HEAD | tee ci-changed-files.txt
             else
                 echo "No BASE_BRANCH environment variable, using master"
                 git diff --name-only master HEAD | tee ci-changed-files.txt