[data_scanner] fix DT_H1 detection

Fix a broken refactor

src/document.sections.cc

@@ -251,7 +251,6 @@ public:
     metadata walk()
     {
         metadata_builder mb;
-        data_token_t dt = DT_INVALID;
         size_t garbage_count = 0;
 
         while (garbage_count < 1000) {
@@ -260,6 +259,7 @@ public:
                 break;
             }
 
+            auto dt = tokenize_res->tr_token;
             element el(tokenize_res->tr_token, tokenize_res->tr_capture);
 
             switch (dt) {

src/file_vtab.cc

@@ -210,6 +210,7 @@ CREATE TABLE lnav_file (
                 loo.loo_include_in_session = true;
                 this->lf_collection.fc_file_names[path] = std::move(loo);
                 lf->set_filename(path);
+                this->lf_collection.regenerate_unique_file_names();
 
                 init_session();
                 load_session();

src/text_format.cc

@@ -45,7 +45,7 @@ detect_text_format(string_fragment sf,
     static const auto MARKDOWN_EXT = ghc::filesystem::path(".markdown");
 
     static const auto MAN_MATCHERS = lnav::pcre2pp::code::from_const(
-        R"(^[A-Z]+\(\d\)\s+)", PCRE2_MULTILINE);
+        R"(^[A-Za-z][A-Za-z\-_\+0-9]+\(\d\)\s+)", PCRE2_MULTILINE);
 
     // XXX This is a pretty crude way of detecting format...
     static const auto PYTHON_MATCHERS = lnav::pcre2pp::code::from_const(

test/document.sections.tests.cc

@@ -125,6 +125,7 @@ DESCRIPTION
 
     auto meta = lnav::document::discover_structure(INPUT, line_range{0, -1});
 
+    CHECK(meta.m_sections_root->hn_named_children.size() == 3);
     meta.m_sections_tree.visit_all([](const auto& intv) {
         auto ser = intv.value.match(
             [](const std::string& name) { return name; },