feat(overlays): add patch-add and patch-remove (#440)

Author: reubeno

docs/reference/overlays.md

@@ -21,6 +21,8 @@ These overlays modify `.spec` files using the structured spec parser, allowing p
 | `spec-prepend-lines` | Prepends lines to the start of a section; **fails if section doesn't exist** | `lines` |
 | `spec-append-lines` | Appends lines to the end of a section; **fails if section doesn't exist** | `lines` |
 | `spec-search-replace` | Regex-based search and replace on spec content | `regex` |
+| `patch-add` | Adds a patch file and registers it in the spec (PatchN tag or %patchlist) | `source` |
+| `patch-remove` | Removes patch files and their spec references matching a glob pattern | `file` |
 
 ### File Overlays
 
@@ -55,8 +57,8 @@ successfully makes a replacement to at least one matching file.
 | Regex | `regex` | Regular expression pattern to match | `spec-search-replace`, `file-search-replace` |
 | Replacement | `replacement` | Literal replacement text; capture group references like `$1` are **not** expanded. Omit or leave empty to delete matched text. | `spec-search-replace`, `file-search-replace`, `file-rename` |
 | Lines | `lines` | Array of text lines to insert | `spec-prepend-lines`, `spec-append-lines`, `file-prepend-lines` |
-| File | `file` | The name of the non-spec file to modify or add | `file-prepend-lines`, `file-search-replace`, `file-add`, `file-remove`, `file-rename` |
-| Source | `source` | Path to source file for `file-add`; relative paths are relative to the config file | `file-add` |
+| File | `file` | The name of the non-spec file to modify or add | `file-prepend-lines`, `file-search-replace`, `file-add`, `file-remove`, `file-rename`, `patch-add` (optional), `patch-remove` |
+| Source | `source` | Path to source file for `file-add` and `patch-add`; relative paths are relative to the config file | `file-add`, `patch-add` |
 
 > **Note:** For `file-rename`, the `replacement` field is a **filename only** (not a path). The file is renamed within its current directory.
 
@@ -198,6 +200,61 @@ file = "oldname.conf"
 replacement = "newname.conf"
 ```
 
+### Adding a Patch
+
+The `patch-add` overlay copies a patch file into the component's sources and registers it
+in the spec. If the spec has a `%patchlist` section, the filename is appended there; otherwise,
+a `PatchN` tag is added with the next available number.
+
+```toml
+[[components.mypackage.overlays]]
+type = "patch-add"
+source = "patches/fix-build-flags.patch"
+description = "Fix compiler flags for our toolchain"
+```
+
+By default, the destination filename is the basename of `source`. Use `file` to override:
+
+```toml
+[[components.mypackage.overlays]]
+type = "patch-add"
+source = "patches/0001-upstream-fix.patch"
+file = "fix-upstream-bug.patch"
+description = "Rename upstream patch for clarity"
+```
+
+### Removing a Patch
+
+The `patch-remove` overlay removes patch references from the spec (`PatchN` tags and/or
+`%patchlist` entries) and deletes the matching patch files from the component's sources.
+The `file` field is a glob pattern matched against patch filenames.
+
+```toml
+[[components.mypackage.overlays]]
+type = "patch-remove"
+file = "fix-old-bug.patch"
+description = "Remove patch that is no longer needed"
+```
+
+Glob patterns can remove multiple patches at once:
+
+```toml
+[[components.mypackage.overlays]]
+type = "patch-remove"
+file = "CVE-*.patch"
+description = "Remove CVE patches that are now upstream"
+```
+
+> **Note:** `patch-remove` does not remove `%patchN` application lines from `%prep`.
+> If the spec uses individual `%patch` directives rather than `%autosetup`, you may need
+> a `spec-search-replace` overlay to remove those lines as well. Similarly, `%autopatch`
+> has `-m` and `-M` options referencing specific patch numbers and will need targeted
+> adjustments.
+
+> **Limitation:** `patch-add` auto-assigns PatchN numbers by scanning existing numeric
+> `PatchN` tags. Macro-based tag numbering (e.g., `Patch%{n}`) is not expanded and may
+> conflict with auto-assigned numbers.
+
 ## Validation
 
 Overlay configurations are validated when the config file is loaded. Validation checks:

internal/app/azldev/core/sources/overlays.go

@@ -45,8 +45,17 @@ func ApplyOverlayToSources(
 	overlay projectconfig.ComponentOverlay,
 	sourcesDirPath, specPath string,
 ) error {
-	if overlay.IsSpecOverlay() {
-		return ApplySpecOverlayToFileInPlace(fs, overlay, specPath)
+	// Apply the spec component, if any.
+	if overlay.ModifiesSpec() {
+		err := ApplySpecOverlayToFileInPlace(fs, overlay, specPath)
+		if err != nil {
+			return err
+		}
+	}
+
+	// Apply the non-spec file component, if any.
+	if !overlay.ModifiesNonSpecFiles() {
+		return nil
 	}
 
 	// Create a destination filesystem confined to the sources directory.
@@ -107,7 +116,7 @@ func ApplySpecOverlayToFileInPlace(fs opctx.FS, overlay projectconfig.ComponentO
 // ApplySpecOverlay applies a spec-based overlay to an opened spec. An error is returned if a non-spec
 // overlay is provided.
 //
-//nolint:cyclop // This function's cyclomatic complexity is inflated by the big switch.
+//nolint:cyclop,funlen // This function's complexity is inflated by the big switch over overlay types.
 func ApplySpecOverlay(overlay projectconfig.ComponentOverlay, openedSpec *spec.Spec) error {
 	//nolint:exhaustive // We intentionally ignore non-spec overlay types.
 	switch overlay.Type {
@@ -148,6 +157,21 @@ func ApplySpecOverlay(overlay projectconfig.ComponentOverlay, openedSpec *spec.S
 		if err != nil {
 			return fmt.Errorf("failed to search and replace in spec:\n%w", err)
 		}
+	case projectconfig.ComponentOverlayAddPatch:
+		destFilename := overlay.Filename
+		if destFilename == "" {
+			destFilename = filepath.Base(overlay.Source)
+		}
+
+		err := openedSpec.AddPatchEntry(overlay.PackageName, destFilename)
+		if err != nil {
+			return fmt.Errorf("failed to add patch entry to spec:\n%w", err)
+		}
+	case projectconfig.ComponentOverlayRemovePatch:
+		err := openedSpec.RemovePatchEntry(overlay.PackageName, overlay.Filename)
+		if err != nil {
+			return fmt.Errorf("failed to remove patch entry from spec:\n%w", err)
+		}
 	default:
 		return fmt.Errorf("invalid overlay type found: %s", overlay.Type)
 	}
@@ -161,20 +185,26 @@ func ApplySpecOverlay(overlay projectconfig.ComponentOverlay, openedSpec *spec.S
 func applyNonSpecOverlay(
 	dryRunnable opctx.DryRunnable, sourceFS, destFS opctx.FS, overlay projectconfig.ComponentOverlay,
 ) error {
-	// See if it's a type of overlay for which `filename` is a literal filename and
-	// never a pattern.
-	if overlay.Type == projectconfig.ComponentOverlayAddFile {
-		// As a precaution, make sure we're not being asked to add a .spec file. To update a spec,
-		// a spec-specific overlay should be used.
+	// Types whose `filename` is a literal filename (not a glob pattern).
+	//nolint:exhaustive // Only literal-filename types are listed; all others use glob matching.
+	switch overlay.Type {
+	case projectconfig.ComponentOverlayAddFile:
 		if isSpecFile(overlay.Filename) {
 			return fmt.Errorf("non-spec overlay not supported on .spec file: %#q", overlay.Filename)
 		}
 
 		return applyNonSpecOverlayToFile(dryRunnable, sourceFS, destFS, overlay, overlay.Filename)
-	}
+	case projectconfig.ComponentOverlayAddPatch:
+		filename := overlay.Filename
+		if filename == "" {
+			filename = filepath.Base(overlay.Source)
+		}
 
-	// For all other cases, `filename` is treated as a glob pattern.
-	return applyNonSpecOverlayToMatchingFiles(dryRunnable, sourceFS, destFS, overlay)
+		return applyNonSpecOverlayToFile(dryRunnable, sourceFS, destFS, overlay, filename)
+	default:
+		// For all other cases, `filename` is treated as a glob pattern.
+		return applyNonSpecOverlayToMatchingFiles(dryRunnable, sourceFS, destFS, overlay)
+	}
 }
 
 func applyNonSpecOverlayToMatchingFiles(
@@ -227,7 +257,8 @@ func applyNonSpecOverlayToMatchingFiles(
 func overlayTypeSupportsMultipleFiles(overlayType projectconfig.ComponentOverlayType) bool {
 	return overlayType == projectconfig.ComponentOverlayPrependLinesToFile ||
 		overlayType == projectconfig.ComponentOverlaySearchAndReplaceInFile ||
-		overlayType == projectconfig.ComponentOverlayRemoveFile
+		overlayType == projectconfig.ComponentOverlayRemoveFile ||
+		overlayType == projectconfig.ComponentOverlayRemovePatch
 }
 
 // applyNonSpecOverlayToFile applies the given overlay to the specified non-spec file.
@@ -249,12 +280,12 @@ func applyNonSpecOverlayToFile(
 		if err != nil {
 			return fmt.Errorf("failed to search and replace in file %#q:\n%w", filePath, err)
 		}
-	case projectconfig.ComponentOverlayAddFile:
+	case projectconfig.ComponentOverlayAddFile, projectconfig.ComponentOverlayAddPatch:
 		err := addNonSpecFile(dryRunnable, sourceFS, destFS, overlay, filePath)
 		if err != nil {
 			return err
 		}
-	case projectconfig.ComponentOverlayRemoveFile:
+	case projectconfig.ComponentOverlayRemoveFile, projectconfig.ComponentOverlayRemovePatch:
 		err := destFS.Remove(filePath)
 		if err != nil {
 			return fmt.Errorf("failed to remove file %#q:\n%w", filePath, err)