system libyaml

[Alessandro-Barbieri]

Can you provide a method to link to systemwide libyaml instead of the bundled one?

[spgarbet]

Why would such a behavior be desirable? Is this a way to get 1.2 support?

[Alessandro-Barbieri]

As now 1.2 isn't ready in libyaml yaml/libyaml#20

You can get an idea of why bundling is bad here https://fedoraproject.org/wiki/Bundled_Libraries?rd=Packaging:Bundled_Libraries

[spgarbet]

The current issue with this is that the current version of libyaml has a patch for indentation that doesn't not exist upstream. Indentation will break unless libyaml accepts that patch upstream if this is implemented.

[Alessandro-Barbieri]

Have you proposed that patch upstream?

[spgarbet]

I inherited this project. The patch was not proposed upstream. I'm doing diffs now to determine the scope of the patch. The secondary investigation is what compile flags exist and do for the libyaml library.

[spgarbet]

I think this is difference.

--- libyaml/src/api.c	2022-02-09 13:06:31.373103740 -0600
+++ yaml/src/api.c	2022-02-09 13:28:42.162132786 -0600
@@ -541,6 +541,18 @@
 }
 
 /*
+ * Set whether or not to indent block sequences in mapping context.
+ */
+
+YAML_DECLARE(void)
+yaml_emitter_set_indent_mapping_sequence(yaml_emitter_t *emitter, int indent_mapping_sequence)
+{
+    assert(emitter);    /* Non-NULL emitter object expected. */
+
+    emitter->indent_mapping_sequence = indent_mapping_sequence;
+}
+
+/*
  * Set the preferred line width.
  */
 
--- libyaml/src/emitter.c	2022-02-09 13:06:31.374103725 -0600
+++ yaml/src/emitter.c	2022-02-09 13:28:45.995087663 -0600
@@ -886,7 +886,9 @@
     if (first)
     {
         if (!yaml_emitter_increase_indent(emitter, 0,
-                    (emitter->mapping_context && !emitter->indention)))
+                    (emitter->mapping_context
+                             && !emitter->indent_mapping_sequence
+                             && !emitter->indention)))
             return 0;
     }
 
@@ -1825,6 +1827,7 @@
 
     emitter->whitespace = is_whitespace;
     emitter->indention = (emitter->indention && is_indention);
+    emitter->open_ended = 0;
 
     return 1;
 }
@@ -1977,6 +1980,10 @@
 
     emitter->whitespace = 0;
     emitter->indention = 0;
+    if (emitter->root_context)
+    {
+        emitter->open_ended = 1;
+    }
 
     return 1;
 }

indent_mapping_sequence.txt

[spgarbet]

I submitted the modifications as a pull request to the libyaml project. They had some outstanding tickets the pull request would solve. There's hope these two can be brought to the same version.

[spgarbet]

One divergence in behavior between a system and the modified one in this package, now has a test case and an isolated patch with Issue #114

[spgarbet]

Pull requests were rejected. I cannot use the system library and get the expected behavior. I tried changed these things to the default of the library and the data.table project immediately complained. There's no way to fix this unfortunately without the upstream library maintainers cooperation, short of changing libraries.

I started this project to change over to a yaml12 supported library: https://github.com/vubiostat/yaml12

I'll make it so it uses the system library.