Check for indent spaces and fixed found problems. Lib C/C++ code is not checked.

.github/workflows/whitespace_checks.yml

@@ -14,6 +14,7 @@ on:
       - '**.sh'
       - '**.cmake'
       - '**.glsl'
+      - '**.lua'
   pull_request:
     paths:
       - '**.txt'
@@ -24,6 +25,7 @@ on:
       - '**.sh'
       - '**.cmake'
       - '**.glsl'
+      - '**.lua'
 
 jobs:
   trailing_whitespaces:
@@ -34,6 +36,32 @@ jobs:
       - name: Check trailing whitespaces
         run: if git ls-files | grep -E '\.txt$|\.md$|\.[ch]$|\.cpp$|\.hpp$|\.sh$|\.cmake$|\.glsl$' | xargs grep -n '\s$'; then echo -e "\033[0;31mFound trailing whitespace"; (exit 1); else (exit 0); fi
 
+  indent_spaces:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      # Line endings are already ensured by .gitattributes
+      # Multiple multline comments in one line is not supported by this check 
+      # and there is no reason to use them
+      # So lines like: "/* */ /*" or "*/ a = 5; /*" will result in error
+      - name: Check for unsupported multiline comments
+        run: |
+          if git ls-files | grep -E '^src/.*\.cpp$|^src/.*\.[ch]$' | xargs grep -n '\*/.*/\*'; then echo -e "\033[0;31mUnsupported combination of multiline comments. New multiline comment should begin on new line."; (exit 1); else (exit 0); fi
+          if git ls-files | grep -E '\.lua$' | xargs grep -n -e '\]\].*--\[\['; then echo -e "\033[0;31mUnsupported combination of multiline comments. New multiline comment should begin on new line."; (exit 1); else (exit 0); fi
+      # This prepare files for final check 
+      # See python script ./util/ci/indent_tab_preprocess.py for details.
+      - name: Preprocess files
+        run: |
+          git ls-files | grep -E '^src/.*\.cpp$|^src/.*\.[ch]$' | xargs -L 1 -P $(($(nproc) + 1)) python3 ./util/ci/indent_tab_preprocess.py "/*" "*/"
+          git ls-files | grep -E '\.lua$' | xargs -L 1 -P $(($(nproc) + 1))  python3 ./util/ci/indent_tab_preprocess.py "--[[" "]]"
+      # Check for bad indent.
+      # This runs over preprocessed files.
+      # If there is any remaining space on line beginning or after tab,
+      # error is generated
+      - name: Check indent spaces
+        run: |
+          if git ls-files | grep -E '^src/.*\.cpp$|^src/.*\.[ch]$|\.lua' | xargs grep -n -P '^\t*[ ]'; then echo -e "\033[0;31mFound incorrect indent whitespaces"; (exit 1); else (exit 0); fi
+
   tabs_lua_api_files:
     runs-on: ubuntu-latest
     steps: