SONARPY-4124 Fixing absolute path resolution on windows during package root resolution (#1084)

GitOrigin-RevId: ee21e5d2291dbf903c193e0d3e84c2566ed96724

Author: joke1196

python-commons/src/main/java/org/sonar/plugins/python/indexer/PackageRootResolver.java

@@ -160,18 +160,36 @@ private static Optional<PackageResolutionResult> trySonarSources(Configuration c
   }
 
   /**
-   * Converts relative path strings to normalized absolute paths under the given base directory.
+   * Converts path strings to normalized absolute paths.
+   *
+   * <p>Relative paths are resolved against the given base directory. Windows-style absolute paths
+   * (e.g. {@code C:\path\to\src} or {@code C:/path/to/src}) are used as-is without prepending the
+   * base directory, which would otherwise produce a nonsensical path on non-Windows systems.
    *
    * <p>Uses {@link Path#normalize()} to resolve {@code .} and {@code ..} components without
    * performing any I/O, so that {@code sonar.sources=.} correctly resolves to the base directory
    * rather than producing an un-normalized path like {@code /project/.}.
    */
   static List<String> toAbsolutePaths(List<String> paths, File baseDir) {
     return paths.stream()
-      .map(path -> new File(baseDir, path).toPath().normalize().toString())
+      .map(path -> {
+        File file = isWindowsAbsolutePath(path) ? new File(path) : new File(baseDir, path);
+        return file.toPath().normalize().toString();
+      })
       .toList();
   }
 
+  /**
+   * Returns {@code true} if the given path is a Windows-style absolute path (e.g. {@code C:\...}
+   * or {@code C:/...}), regardless of the current operating system.
+   */
+  private static boolean isWindowsAbsolutePath(String path) {
+    return path.length() >= 3
+      && Character.isLetter(path.charAt(0))
+      && path.charAt(1) == ':'
+      && (path.charAt(2) == '\\' || path.charAt(2) == '/');
+  }
+
   private static List<String> findConventionalFolders(File baseDir) {
     List<String> folders = new ArrayList<>();
     for (String folderName : CONVENTIONAL_FOLDERS) {
@@ -186,8 +204,19 @@ private static List<String> findConventionalFolders(File baseDir) {
   private static List<String> adjustRoots(List<String> roots, File baseDir) {
     return roots.stream()
       .map(root -> {
-        File rootFile = new File(root).isAbsolute() ? new File(root) : new File(baseDir, root);
-        return adjustPackageRoot(rootFile, baseDir);
+        File rootAsFile = new File(root);
+        if (rootAsFile.isAbsolute()) {
+          // Native absolute path (works on any OS, including Windows running on Windows).
+          return adjustPackageRoot(rootAsFile, baseDir);
+        }
+        if (isWindowsAbsolutePath(root)) {
+          // Windows-style absolute path (e.g. C:\src) on a non-Windows system: File.isAbsolute()
+          // returns false, so we must not pass it to new File(baseDir, root) or getAbsolutePath()
+          // would prepend the JVM working directory. Return as-is; __init__.py traversal is not
+          // meaningful for a foreign-OS path.
+          return root;
+        }
+        return adjustPackageRoot(new File(baseDir, root), baseDir);
       })
       .distinct()
       .toList();

python-commons/src/test/java/org/sonar/plugins/python/indexer/PackageRootResolverTest.java

@@ -152,6 +152,50 @@ void toAbsolutePaths_dotPath_normalizedToBaseDir() {
     assertThat(result.get(0)).doesNotEndWith("\\.");
   }
 
+  // ─── toAbsolutePaths() — Windows path handling ───────────────────────────
+
+  @Test
+  void toAbsolutePaths_windowsAbsolutePath_notPrependedWithBaseDir() {
+    // When sonar.sources contains a Windows-style absolute path (e.g. from a Windows scanner),
+    // it must NOT be prepended with the base directory on a non-Windows system.
+    File baseDir = new File("/project/base");
+    String windowsAbsPath = "C:\\Users\\user\\mixed-language-build";
+
+    List<String> result = PackageRootResolver.toAbsolutePaths(List.of(windowsAbsPath), baseDir);
+
+    // Must not produce "/project/base/" prepended to the Windows path
+    assertThat(result).containsExactly("C:\\Users\\user\\mixed-language-build");
+  }
+
+  @Test
+  void toAbsolutePaths_windowsAbsolutePathWithForwardSlashes_notPrependedWithBaseDir() {
+    // Windows paths may also use forward slashes; they are normalised by Path.normalize()
+    File baseDir = new File("/project/base");
+    String windowsAbsPath = "C:/Users/user/mixed-language-build";
+
+    List<String> result = PackageRootResolver.toAbsolutePaths(List.of(windowsAbsPath), baseDir);
+
+    // Must not produce "/project/base/" prepended to the Windows path
+    // Forward slashes are preserved as-is by Path.normalize() on non-Windows systems
+    assertThat(result).hasSize(1);
+    assertThat(result.get(0)).isIn("C:\\Users\\user\\mixed-language-build","C:/Users/user/mixed-language-build");
+  }
+
+  @Test
+  void trySonarSources_windowsAbsolutePath_usedDirectlyNotPrependedWithBaseDir() throws IOException {
+    // Full integration: build file exists, sonar.sources has a Windows absolute path.
+    // The resolved root should be derived from the Windows path, not baseDir + Windows path.
+    Files.writeString(tempDir.resolve("pyproject.toml"), "[project]\nname = \"myproject\"\n");
+    File baseDir = tempDir.toFile();
+    String windowsAbsPath = "C:\\Users\\user\\mixed-language-build";
+
+    PackageResolutionResult result = PackageRootResolver.resolve(mockFileSystem(baseDir), sonarSources(windowsAbsPath));
+
+    assertThat(result.method()).isEqualTo(PackageResolutionResult.ResolutionMethod.SONAR_SOURCES);
+    assertThat(result.roots()).hasSize(1);
+    assertThat(result.roots()).containsExactly("C:\\Users\\user\\mixed-language-build");
+  }
+
   // ─── adjustPackageRoot() — migrated from PythonIndexerTest ────────────────
 
   @Test