CFE-2663: Select empty region at end of file when select_end_match_eof is set

cf-agent/files_editline.c

@@ -869,7 +869,13 @@ If no such region matches, begin_ptr and end_ptr should point to NULL
             {
                 if (!include_start)
                 {
-                    if (ip->next == NULL)
+                    /* The start delimiter is the last line of the file, so the
+                     * region (which excludes the delimiter) is empty and sits
+                     * at end of file. Reject it only when select_end_match_eof
+                     * is not set. Otherwise the empty region at EOF is a valid,
+                     * selectable region so that e.g. a trailing INI section can
+                     * still be populated (CFE-2663). */
+                    if (ip->next == NULL && !a->region.select_end_match_eof)
                     {
                         Log(LOG_LEVEL_VERBOSE,
                              "The promised start pattern '%s' found an empty region at the end of file '%s'",

tests/acceptance/31_tickets/CFE-2663/test.cf

@@ -0,0 +1,81 @@
+body file control
+{
+  inputs => { "../../default.sub.cf" };
+}
+
+bundle agent __main__
+{
+  methods:
+    "bundlesequence" usebundle => default("$(this.promise_filename)");
+}
+
+bundle agent init
+{
+  vars:
+      # No trailing newline in the strings, so the "[section2]" header is
+      # genuinely the last line of the "actual" file. The region selected for
+      # section2 is therefore empty and sits at the end of the file.
+      "actual" string => "[section]
+keyone=valueone
+[section2]";
+
+      "expected" string => "[section]
+keyone=valueone
+[section2]
+keytwo=valuetwo";
+
+      "files" slist => { "actual", "expected" };
+
+  files:
+      "$(G.testfile).$(files)"
+        create => "true",
+        edit_line => init_insert("$(init.$(files))"),
+        edit_defaults => init_empty;
+}
+
+bundle edit_line init_insert(str)
+{
+  insert_lines:
+      "$(str)";
+}
+
+body edit_defaults init_empty
+{
+      empty_file_before_editing => "true";
+}
+
+bundle agent test
+{
+  meta:
+      "description"
+        string => "Insertion into an empty trailing region (the select_start delimiter is the last line of the file) must succeed when select_end_match_eof is true",
+        meta => { "CFE-2663" };
+
+  files:
+      "$(G.testfile).actual"
+        edit_line => insert_into_trailing_section;
+}
+
+bundle edit_line insert_into_trailing_section
+{
+  insert_lines:
+      "keytwo=valuetwo"
+        select_region => ini_section("section2");
+}
+
+body select_region ini_section(x)
+# @brief Restrict the edit to the lines in section [x], matching to EOF when
+# [x] is the final section in the file.
+{
+      select_start => "\[$(x)\]\s*";
+      select_end => "\[.*\]\s*";
+      select_end_match_eof => "true";
+}
+
+bundle agent check
+{
+  methods:
+      "any" usebundle => dcs_check_diff("$(G.testfile).actual",
+                                        "$(G.testfile).expected",
+                                        "$(this.promise_filename)");
+}