diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index f0a49b529b7..93a6b334468 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -522,10 +522,10 @@ jobs:
         uses: ./
         with:
           files: |
-            entrypoint.sh
+            get-changed-paths.sh
             *.sh
       - name: Verify all_changed_files files has no duplicates
-        if: contains(steps.changed-files-specific-duplicate-output.outputs.all_changed_files, 'entrypoint.sh')
+        if: contains(steps.changed-files-specific-duplicate-output.outputs.all_changed_files, 'get-changed-paths.sh')
         run: |
           ALL_CHANGED_FILES=(${{ steps.changed-files-specific-duplicate-output.outputs.all_changed_files }})
           UNIQUE_ALL_CHANGED_FILES=$(echo "$ALL_CHANGED_FILES" | tr ' ' '\n' | sort -u | xargs)
@@ -537,7 +537,7 @@ jobs:
         shell:
           bash
       - name: Verify all_changed_and_modified_files files has no duplicates
-        if: contains(steps.changed-files-specific-duplicate-output.outputs.all_changed_and_modified_files, 'entrypoint.sh')
+        if: contains(steps.changed-files-specific-duplicate-output.outputs.all_changed_and_modified_files, 'get-changed-paths.sh')
         run: |
           ALL_CHANGED_AND_MODIFIED_FILES=(${{ steps.changed-files-specific-duplicate-output.outputs.all_changed_and_modified_files }})
           UNIQUE_ALL_CHANGED_AND_MODIFIED_FILES=$(echo "$ALL_CHANGED_AND_MODIFIED_FILES" | tr ' ' '\n' | sort -u | xargs)
@@ -549,7 +549,7 @@ jobs:
         shell:
           bash
       - name: Verify all_modified_files files has no duplicates
-        if: contains(steps.changed-files-specific-duplicate-output.outputs.all_modified_files, 'entrypoint.sh')
+        if: contains(steps.changed-files-specific-duplicate-output.outputs.all_modified_files, 'get-changed-paths.sh')
         run: |
           ALL_MODIFIED_FILES=(${{ steps.changed-files-specific-duplicate-output.outputs.all_modified_files }})
           UNIQUE_ALL_MODIFIED_FILES=$(echo "$ALL_MODIFIED_FILES" | tr ' ' '\n' | sort -u | xargs)
diff --git a/action.yml b/action.yml
index 28a4e1a7cee..47f6744c7fe 100644
--- a/action.yml
+++ b/action.yml
@@ -151,40 +151,32 @@ runs:
   using: "composite"
   steps:
     - run: |
-        # "Set base sha..."
-        if [[ -n "${{ inputs.since }}" ]]; then
-          BASE_SHA=$(git log --format="%H" --date=local --since="${{ inputs.since }}" --reverse | head -n 1)
-          if [[ -z "$BASE_SHA" ]]; then
-            echo "::warning::The BASE_SHA for date '${{ inputs.since }}' couldn't be determined."
-          fi
-          echo "::set-output name=base_sha::$BASE_SHA"
-        elif [[ -n "${{ inputs.base_sha }}" ]]; then
-          echo "::set-output name=base_sha::${{ inputs.base_sha }}"
-        elif [[ "${{ inputs.since_last_remote_commit }}" == "true" ]]; then
-          LAST_REMOTE_COMMIT="${{ github.event.before }}"
-          if [[ -z "$LAST_REMOTE_COMMIT" || "$LAST_REMOTE_COMMIT" == "0000000000000000000000000000000000000000" ]]; then
-            LAST_REMOTE_COMMIT=$(git rev-parse $(git branch -r --sort=-committerdate | head -1))
-          fi
-          if [[ "${{ inputs.sha }}" == "$LAST_REMOTE_COMMIT" ]]; then
-            LAST_REMOTE_COMMIT=$(git rev-parse "${{ inputs.sha }}^1")
-          fi
-          echo "::set-output name=base_sha::$LAST_REMOTE_COMMIT"
-        fi
+        # "Calculate the base sha..."
+        bash $GITHUB_ACTION_PATH/get-base-sha.sh
       id: base-sha
       shell: bash
+      env:
+        GITHUB_WORKSPACE: ${{ github.workspace }}
+        GITHUB_EVENT_BEFORE: ${{ github.event.before }}
+        # INPUT_<VARIABLE_NAME> is not available in Composite run steps
+        # https://docs.github.com/en/actions/creating-actions/metadata-syntax-for-github-actions#example-specifying-inputs
+        INPUT_SINCE: ${{ inputs.since }}
+        INPUT_BASE_SHA: ${{ inputs.base_sha }}
+        INPUT_SHA: ${{ inputs.sha }}
+        INPUT_PATH: ${{ inputs.path }}
+        INPUT_SINCE_LAST_REMOTE_COMMIT: ${{ inputs.since_last_remote_commit }}
     - run: |
-        # "Set the sha..."
-        if [[ -n "${{ inputs.until }}" ]]; then
-          SHA=$(git log -1 --format="%H" --date=local --until="${{ inputs.until }}")
-          if [[ -z "$SHA" ]]; then
-            echo "::warning::The SHA for date '${{ inputs.until }}' couldn't be determined, falling back to the current sha."
-          fi
-          echo "::set-output name=sha::$SHA"
-        else
-          echo "::set-output name=sha::${{ inputs.sha }}"
-        fi
+        # "Calculate the sha..."
+        bash $GITHUB_ACTION_PATH/get-sha.sh
       id: sha
       shell: bash
+      env:
+        GITHUB_WORKSPACE: ${{ github.workspace }}
+        # INPUT_<VARIABLE_NAME> is not available in Composite run steps
+        # https://docs.github.com/en/actions/creating-actions/metadata-syntax-for-github-actions#example-specifying-inputs
+        INPUT_UNTIL: ${{ inputs.until }}
+        INPUT_SHA: ${{ inputs.sha }}
+        INPUT_PATH: ${{ inputs.path }}
     - run: |
         # "Calculating the previous and current SHA..."
         bash $GITHUB_ACTION_PATH/diff-sha.sh
@@ -195,9 +187,9 @@ runs:
         GITHUB_REPOSITORY: ${{ github.repository }}
         GITHUB_BASE_REF: ${{ github.base_ref }}
         GITHUB_HEAD_REF: ${{ github.head_ref }}
-        GITHUB_ACTION_PATH: ${{ github.action_path }}
         GITHUB_WORKSPACE: ${{ github.workspace }}
         GITHUB_PULL_REQUEST_BASE_SHA: ${{ github.event.pull_request.base.sha }}
+        GITHUB_EVENT_BEFORE: ${{ github.event.before }}
         # INPUT_<VARIABLE_NAME> is not available in Composite run steps
         # https://docs.github.com/en/actions/creating-actions/metadata-syntax-for-github-actions#example-specifying-inputs
         INPUT_SHA: ${{ steps.sha.outputs.sha }}
@@ -209,22 +201,21 @@ runs:
       with:
         files: ${{ inputs.files }}
         files-separator: ${{ inputs.files_separator }}
-        escape-paths: true
         excluded-files: ${{ inputs.files_ignore }}
         excluded-files-separator: ${{ inputs.files_ignore_separator }}
         files-from-source-file: ${{ inputs.files_from_source_file }}
         excluded-files-from-source-file: ${{ inputs.files_ignore_from_source_file}}
+        escape-paths: true
         working-directory: ${{ inputs.path }}
         base-sha: ${{ steps.changed-files-diff-sha.outputs.previous_sha }}
         sha: ${{ steps.changed-files-diff-sha.outputs.current_sha }}
         include-deleted-files: true
         separator: "|"
     - run: |
-        bash $GITHUB_ACTION_PATH/entrypoint.sh
+        bash $GITHUB_ACTION_PATH/get-changed-paths.sh
       id: changed-files
       shell: bash
       env:
-        GITHUB_ACTION_PATH: ${{ github.action_path }}
         GITHUB_WORKSPACE: ${{ github.workspace }}
         # INPUT_<VARIABLE_NAME> is not available in Composite run steps
         # https://docs.github.com/en/actions/creating-actions/metadata-syntax-for-github-actions#example-specifying-inputs
@@ -242,6 +233,7 @@ runs:
         INPUT_DIFF_RELATIVE: ${{ inputs.diff_relative }}
         INPUT_DIR_NAMES: ${{ inputs.dir_names }}
         INPUT_JSON: ${{ inputs.json }}
+        INPUT_HAS_CUSTOM_PATTERNS: ${{ steps.glob.outputs.has-custom-patterns }}
 
 branding:
   icon: file-text
diff --git a/diff-sha.sh b/diff-sha.sh
index 9116f3ba3fd..434f2899c6b 100644
--- a/diff-sha.sh
+++ b/diff-sha.sh
@@ -57,30 +57,29 @@ else
 fi
 
 if [[ -z $GITHUB_BASE_REF ]]; then
-  TARGET_BRANCH=${GITHUB_REF/refs\/heads\//}
-  CURRENT_BRANCH=$TARGET_BRANCH
-
-  echo "::debug::GITHUB_BASE_REF unset using $TARGET_BRANCH..."
+  TARGET_BRANCH=${GITHUB_REF/refs\/heads\//} && exit_status=$? || exit_status=$?
+  CURRENT_BRANCH=$TARGET_BRANCH && exit_status=$? || exit_status=$?
 
   if [[ -z $INPUT_BASE_SHA ]]; then
-    git fetch --no-tags -u --progress origin --depth=2 "${TARGET_BRANCH}":"${TARGET_BRANCH}" && exit_status=$? || exit_status=$?
+    PREVIOUS_SHA=$GITHUB_EVENT_BEFORE
+
+    if [[ -z "$PREVIOUS_SHA" || "$PREVIOUS_SHA" == "0000000000000000000000000000000000000000" ]]; then
+      PREVIOUS_SHA=$(git rev-parse "$(git branch -r --sort=-committerdate | head -1)")
+    fi
 
-    if [[ $(git rev-list --count "HEAD") -gt 1 ]]; then
-      PREVIOUS_SHA=$(git rev-parse "@~1" 2>&1) && exit_status=$? || exit_status=$?
-      echo "::debug::Previous SHA: $PREVIOUS_SHA"
-    else
-      PREVIOUS_SHA=$CURRENT_SHA; exit_status=$?
+    if [[ "$PREVIOUS_SHA" == "$CURRENT_SHA" ]]; then
       INITIAL_COMMIT="true"
       echo "::debug::Initial commit detected"
-      echo "::debug::Previous SHA: $PREVIOUS_SHA"
     fi
   else
-    PREVIOUS_SHA=$INPUT_BASE_SHA; exit_status=$?
+    PREVIOUS_SHA=$INPUT_BASE_SHA
     TARGET_BRANCH=$(git name-rev --name-only "$PREVIOUS_SHA" 2>&1) && exit_status=$? || exit_status=$?
-    echo "::debug::Previous SHA: $PREVIOUS_SHA"
-    echo "::debug::Target branch: $TARGET_BRANCH"
+    CURRENT_BRANCH=$TARGET_BRANCH
   fi
 
+  echo "::debug::Target branch $TARGET_BRANCH..."
+  echo "::debug::Current branch $CURRENT_BRANCH..."
+
   echo "::debug::Verifying the previous commit SHA: $PREVIOUS_SHA"
   git rev-parse --quiet --verify "$PREVIOUS_SHA^{commit}" 1>/dev/null 2>&1 && exit_status=$? || exit_status=$?
 
diff --git a/get-base-sha.sh b/get-base-sha.sh
new file mode 100644
index 00000000000..c2fcee3c283
--- /dev/null
+++ b/get-base-sha.sh
@@ -0,0 +1,34 @@
+#!/usr/bin/env bash
+
+set -eu
+
+if [[ -n $INPUT_PATH ]]; then
+  REPO_DIR="$GITHUB_WORKSPACE/$INPUT_PATH"
+
+  echo "Resolving repository path: $REPO_DIR"
+  if [[ ! -d "$REPO_DIR" ]]; then
+    echo "::error::Invalid repository path: $REPO_DIR"
+    exit 1
+  fi
+  cd "$REPO_DIR"
+fi
+
+if [[ -n "$INPUT_SINCE" ]]; then
+  BASE_SHA=$(git log --format="%H" --date=local --since="$INPUT_SINCE" --reverse | head -n 1)
+  if [[ -z "$BASE_SHA" ]]; then
+    echo "::warning::The BASE_SHA for date '$INPUT_SINCE' couldn't be determined."
+  fi
+  echo "::set-output name=base_sha::$BASE_SHA"
+elif [[ -n "$INPUT_BASE_SHA" ]]; then
+  echo "::set-output name=base_sha::$INPUT_BASE_SHA"
+elif [[ "$INPUT_SINCE_LAST_REMOTE_COMMIT" == "true" ]]; then
+  LAST_REMOTE_COMMIT="$GITHUB_EVENT_BEFORE"
+
+  if [[ -z "$LAST_REMOTE_COMMIT" || "$LAST_REMOTE_COMMIT" == "0000000000000000000000000000000000000000" ]]; then
+    LAST_REMOTE_COMMIT=$(git rev-parse "$(git branch -r --sort=-committerdate | head -1)")
+  fi
+  if [[ "$INPUT_SHA" == "$LAST_REMOTE_COMMIT" ]]; then
+    LAST_REMOTE_COMMIT=$(git rev-parse "$INPUT_SHA^1")
+  fi
+  echo "::set-output name=base_sha::$LAST_REMOTE_COMMIT"
+fi
diff --git a/entrypoint.sh b/get-changed-paths.sh
similarity index 99%
rename from entrypoint.sh
rename to get-changed-paths.sh
index 6866f6321e7..fe63604b187 100755
--- a/entrypoint.sh
+++ b/get-changed-paths.sh
@@ -81,7 +81,7 @@ echo "Retrieving changes between $INPUT_PREVIOUS_SHA ($INPUT_TARGET_BRANCH) →
 
 echo "Getting diff..."
 
-if [[ -z "$INPUT_FILES_PATTERN_FILE" ]]; then
+if [[ "$INPUT_HAS_CUSTOM_PATTERNS" == "false" ]]; then
   if [[ "$INPUT_JSON" == "false" ]]; then
     ADDED=$(get_diff "$INPUT_PREVIOUS_SHA" "$INPUT_CURRENT_SHA" A | awk -v d="$INPUT_SEPARATOR" '{s=(NR==1?s:s d)$0}END{print s}')
     COPIED=$(get_diff "$INPUT_PREVIOUS_SHA" "$INPUT_CURRENT_SHA" C | awk -v d="$INPUT_SEPARATOR" '{s=(NR==1?s:s d)$0}END{print s}')
diff --git a/get-sha.sh b/get-sha.sh
new file mode 100644
index 00000000000..ede5529c090
--- /dev/null
+++ b/get-sha.sh
@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+
+set -eu
+
+if [[ -n $INPUT_PATH ]]; then
+  REPO_DIR="$GITHUB_WORKSPACE/$INPUT_PATH"
+
+  echo "Resolving repository path: $REPO_DIR"
+  if [[ ! -d "$REPO_DIR" ]]; then
+    echo "::error::Invalid repository path: $REPO_DIR"
+    exit 1
+  fi
+  cd "$REPO_DIR"
+fi
+
+if [[ -n "$INPUT_UNTIL" ]]; then
+  SHA=$(git log -1 --format="%H" --date=local --until="$INPUT_UNTIL")
+  if [[ -z "$SHA" ]]; then
+    echo "::warning::The SHA for date '$INPUT_UNTIL' couldn't be determined, falling back to the current sha."
+  fi
+  echo "::set-output name=sha::$SHA"
+else
+  echo "::set-output name=sha::$INPUT_SHA"
+fi