From: Matthew Fernandez <matthew.fernandez@gmail.com>
Date: Tue, 6 Jul 2021 00:38:44 +0000 (-0700)
Subject: gxl2gv: fix: recognize and handle HTML-like strings
X-Git-Tag: 2.48.0~3^2
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=38763516885bd90b5e1b6806a002e81aa2e75f3d;p=graphviz

gxl2gv: fix: recognize and handle HTML-like strings

When translating a Graphviz file through gv2gxl, HTML-like and non-HTML-like
strings would be translated identically, resulting in a loss of information.
This was fixed in the series merged in d44d19c86f0f469d1c76ce0d7630c8e0ac85e993.
However, to take this through to completion and make round-tripping such strings
possible, changes to gxl2gv were also required.

The present commit updates gxl2gv to recognize the new ‘kind’ GXL attribute that
gv2gxl uses to indicate a string originated as an HTML-like string. The output
of gxl2gv now correctly translates this back to an HTML-like string. Fixes #517.

Note that this fix is orthogonal to the behavior when using an HTML-like and
non-HTML-like string with the same content. It is still not possible to do this
without confusing the internal string interning dictionary (#2089).
---

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0844b548e..49e7378f4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -33,6 +33,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - a Bashism removed from the Autotools build system
 - when Criterion is available, the `command_line` test binary is no longer built
   and installed by default, but rather during `make check`
+- round-tripping a file through ``gv2gxl`` and then ``gxl2gv`` no longer causes
+  HTML-like labels to become non-HTML like labels #517
 
 ## [2.47.3] - 2021-06-19
 
diff --git a/cmd/tools/gxl2gv.c b/cmd/tools/gxl2gv.c
index 73bed1c8d..df5d8400a 100644
--- a/cmd/tools/gxl2gv.c
+++ b/cmd/tools/gxl2gv.c
@@ -40,6 +40,7 @@ typedef enum {
   TAG_GRAPH,
   TAG_NODE,
   TAG_EDGE,
+  TAG_HTML_LIKE_STRING,
 } attr_t;
 
 typedef struct slist slist;
@@ -553,6 +554,8 @@ startElementHandler(void *userData, const char *name, const char **atts)
 		ud->globalAttrType = TAG_EDGE;
 	    else if (strcmp("graph", atts[pos]) == 0)
 		ud->globalAttrType = TAG_GRAPH;
+	    else if (strcmp("HTML-like string", atts[pos]) == 0)
+		ud->globalAttrType = TAG_HTML_LIKE_STRING;
 	} else {
 	    ud->globalAttrType = TAG_NONE;
 	}
@@ -654,6 +657,9 @@ static void endElementHandler(void *userData, const char *name)
 	case TAG_GRAPH:
 	    setGraphAttr(G, name, value, ud);
 	    break;
+	case TAG_HTML_LIKE_STRING:
+	    setAttr(name, value, ud, true);
+	    break;
 	}
 	free(dynbuf);
 	ud->globalAttrType = TAG_NONE;
diff --git a/rtest/test_regression.py b/rtest/test_regression.py
index 8380564e5..5306fcd3e 100644
--- a/rtest/test_regression.py
+++ b/rtest/test_regression.py
@@ -243,7 +243,6 @@ def test_167():
   # Graphviz should not have caused a segfault
   assert ret != -signal.SIGSEGV, "Graphviz segfaulted"
 
-@pytest.mark.xfail(strict=True)
 @pytest.mark.skipif(shutil.which("gv2gxl") is None or
                     shutil.which("gxl2gv") is None,
                     reason="GXL tools not available")