2 files changed, 42 insertions, 4 deletions
diff --git a/internal/processor/markdown_test.go b/internal/processor/markdown_test.go
index a17b704..2445b53 100644
--- a/internal/processor/markdown_test.go
+++ b/internal/processor/markdown_test.go
@@ -3,7 +3,10 @@ package processor
 import (
 	"os"
 	"path/filepath"
+	"runtime"
 	"testing"
+
+	"codeberg.org/snonux/snonux/internal/config"
 )
 
 func TestFindLocalImages(t *testing.T) {
@@ -88,3 +91,35 @@ func TestFindLocalImages(t *testing.T) {
 		})
 	}
 }
+
+func TestRun_UnreadableMarkdownPreScanFails(t *testing.T) {
+	t.Parallel()
+	if runtime.GOOS == "windows" {
+		t.Skip("chmod does not reliably deny read for owned files on Windows")
+	}
+
+	base := t.TempDir()
+	inputDir := filepath.Join(base, "inbox")
+	outputDir := filepath.Join(base, "out")
+	if err := os.MkdirAll(inputDir, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.MkdirAll(outputDir, 0o755); err != nil {
+		t.Fatal(err)
+	}
+
+	mdPath := filepath.Join(inputDir, "note.md")
+	if err := os.WriteFile(mdPath, []byte("# x\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Chmod(mdPath, 0); err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { _ = os.Chmod(mdPath, 0o644) })
+
+	cfg := &config.Config{InputDir: inputDir, OutputDir: outputDir}
+	_, err := Run(cfg)
+	if err == nil {
+		t.Fatal("Run: expected error when markdown pre-scan cannot read a .md file")
+	}
+}
diff --git a/internal/processor/processor.go b/internal/processor/processor.go
index 2e2d626..b6fa40b 100644
--- a/internal/processor/processor.go
+++ b/internal/processor/processor.go
@@ -33,7 +33,10 @@ func Run(cfg *config.Config) (int, error) {
 
 	// Pre-scan markdown files to discover which image filenames they claim.
 	// Claimed images are excluded from independent processing.
-	claimed := claimedByMarkdown(entries, cfg.InputDir)
+	claimed, err := claimedByMarkdown(entries, cfg.InputDir)
+	if err != nil {
+		return 0, err
+	}
 
 	count := 0
 
@@ -59,7 +62,7 @@ func Run(cfg *config.Config) (int, error) {
 // claimedByMarkdown scans all .md entries in inputDir and returns a set of
 // image filenames that are referenced within those markdown files.
 // Those images should be embedded in the markdown post, not processed alone.
-func claimedByMarkdown(entries []os.DirEntry, inputDir string) map[string]bool {
+func claimedByMarkdown(entries []os.DirEntry, inputDir string) (map[string]bool, error) {
 	claimed := make(map[string]bool)
 
 	for _, entry := range entries {
@@ -70,7 +73,7 @@ func claimedByMarkdown(entries []os.DirEntry, inputDir string) map[string]bool {
 		mdPath := filepath.Join(inputDir, entry.Name())
 		data, err := os.ReadFile(mdPath)
 		if err != nil {
-			continue
+			return nil, fmt.Errorf("read markdown for image claims %s: %w", entry.Name(), err)
 		}
 
 		for _, imgName := range findLocalImages(string(data), inputDir) {
@@ -78,7 +81,7 @@ func claimedByMarkdown(entries []os.DirEntry, inputDir string) map[string]bool {
 		}
 	}
 
-	return claimed
+	return claimed, nil
 }
 
 // processFile processes a single input file into a new post directory.