gout

commit d0ff6f6ced5c7d330536644517596a5814b14918
parent 573d74cb9c9b09003bb8fec0ab0a48ca1e0fe1ac
Author: Chris Bracken <chris@bracken.jp>
Date:   Sat,  6 Jun 2026 14:52:04 +0900

writer/atom: fix RFC 4287 violation

Emit an empty title in atom_add_commit when a commit's summary is NULL
or empty to comply with RFC 4287 which requires a <title> tag.

Also fix a potential use-after-free issue with baseurl. Given the
current implementation gets this from Options (i.e. the command-line)
this shouldn't be an issue, but it avoids making assumptions about
implementation details.

Diffstat:
M
src/writer/atom/atom.c
 | 
26
+++++++++++++++-----------
M
src/writer/atom/atom_tests.c
 | 
29
++++++++++++++++++++++++++++-

2 files changed, 43 insertions(+), 12 deletions(-)
diff --git a/src/writer/atom/atom.c b/src/writer/atom/atom.c
@@ -12,7 +12,7 @@
 
 struct Atom {
   const GitRepo* repo;
-  const char* baseurl;
+  char* baseurl;
   FILE* out;
   size_t remaining_commits;
 };
@@ -22,7 +22,7 @@ Atom* atom_create(const GitRepo* repo, FILE* out) {
   assert(out != NULL);
   Atom* atom = ecalloc(1, sizeof(Atom));
   atom->repo = repo;
-  atom->baseurl = "";
+  atom->baseurl = estrdup("");
   atom->out = out;
   atom->remaining_commits = 100;
   return atom;
@@ -32,6 +32,7 @@ void atom_free(Atom* atom) {
   if (!atom) {
     return;
   }
+  free(atom->baseurl);
   atom->out = NULL;
   free(atom);
 }
@@ -39,7 +40,8 @@ void atom_free(Atom* atom) {
 void atom_set_baseurl(Atom* atom, const char* baseurl) {
   assert(atom != NULL);
   assert(baseurl != NULL);
-  atom->baseurl = baseurl;
+  free(atom->baseurl);
+  atom->baseurl = estrdup(baseurl);
 }
 
 void atom_begin(Atom* atom) {
@@ -90,16 +92,18 @@ void atom_add_commit(Atom* atom,
   print_time_z(out, commit->commit_time);
   fprintf(out, "</updated>\n");
 
-  if (commit->summary) {
-    fprintf(out, "<title>");
-    if (tag && tag[0] != '\0') {
-      fprintf(out, "[");
-      print_xml_encoded(out, tag);
-      fprintf(out, "]");
-    }
+  fprintf(out, "<title>");
+  if (tag && tag[0] != '\0') {
+    fprintf(out, "[");
+    print_xml_encoded(out, tag);
+    fprintf(out, "] ");
+  }
+  if (commit->summary && commit->summary[0] != '\0') {
     print_xml_encoded(out, commit->summary);
-    fprintf(out, "</title>\n");
+  } else {
+    fprintf(out, "Commit %.7s", commit->oid);
   }
+  fprintf(out, "</title>\n");
   fprintf(out, "<link rel=\"alternate\" ");
   if (strlen(content_type) > 0) {
     fprintf(out, "type=\"%s\" ", content_type);
diff --git a/src/writer/atom/atom_tests.c b/src/writer/atom/atom_tests.c
@@ -68,7 +68,7 @@ UTEST(atom, add_commit) {
                       "<id>abc1234567890</id>",                       //
                       "<published>2023-12-08T10:30:00Z</published>",  //
                       "<updated>2023-12-08T11:30:00Z</updated>",      //
-                      "<title>[v1.0]Fix a bug</title>",               //
+                      "<title>[v1.0] Fix a bug</title>",              //
                       "<link rel=\"alternate\" type=\"text/html\" "
                       "href=\"https://example.com/commit/abc.html\" />",  //
                       "<author>",                                         //
@@ -201,3 +201,30 @@ UTEST(atom, url_concatenation) {
     free(buf);
   }
 }
+
+UTEST(atom, empty_summary) {
+  char* buf = NULL;
+  size_t size = 0;
+  FILE* out = open_memstream(&buf, &size);
+  ASSERT_NE(NULL, out);
+
+  GitRepo repo = {.short_name = "test-repo"};
+  Atom* atom = atom_create(&repo, out);
+
+  GitCommit commit = {
+      .oid = "1234567890abcdef",
+      .summary = NULL,
+      .author_name = "Test User",
+      .author_email = "test@example.com",
+  };
+
+  atom_add_commit(atom, &commit, "commit/abc.html", "text/html", "");
+  atom_free(atom);
+  fflush(out);
+  fclose(out);
+
+  ASSERT_NE(NULL, buf);
+  EXPECT_TRUE(strstr(buf, "<title>Commit 1234567</title>") != NULL);
+
+  free(buf);
+}