From: Matthew Fernandez <matthew.fernandez@gmail.com>
Date: Mon, 14 Mar 2022 05:27:02 +0000 (-0700)
Subject: Revert "rewrite indexOf"
X-Git-Tag: 4.0.0~169^2
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=51d787ece01fb4443db5eabd6932046b7b715dbc;p=graphviz

Revert "rewrite indexOf"

This reverts commit 84efe93d5c5a4da0e778dbf01ed8550d2d774fdf.

Gitlab: fixes #2211
---

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f2510b3af..8dc35e90d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - spurious "no hard-coded metrics" warnings on labels with empty lines #2179
 - fixed corruption of user shape characteristics during EPSF initialization
 - output formats canon, dot, and xdot are not completely faithful to input #2184
+- gvpr index function produces wrong results #2211. This was a regression in
+  Graphviz 2.47.0.
 
 ## [3.0.0] – 2022-02-26
 
diff --git a/lib/gvpr/actions.c b/lib/gvpr/actions.c
index c2f4b4b3a..6d2713366 100644
--- a/lib/gvpr/actions.c
+++ b/lib/gvpr/actions.c
@@ -56,8 +56,22 @@ Agraph_t *sameG(void *p1, void *p2, char *fn, char *msg)
  */
 int indexOf(char *s1, char *s2)
 {
-    char *s = strstr(s1, s2);
-    return s == NULL ? -1 : (int)(s1 - s);
+    char c1 = *s2;
+    char c;
+    char *p;
+    int len2;
+
+    if (c1 == '\0')
+	return 0;
+    p = s1;
+    len2 = strlen(s2) - 1;
+    while ((c = *p++)) {
+	if (c != c1)
+	    continue;
+	if (strncmp(p, s2 + 1, len2) == 0)
+	    return ((p - s1) - 1);
+    }
+    return -1;
 }
 
 /* rindexOf:
diff --git a/rtest/test_regression.py b/rtest/test_regression.py
index 2bfca5190..27dd231dc 100644
--- a/rtest/test_regression.py
+++ b/rtest/test_regression.py
@@ -1563,7 +1563,6 @@ def test_2193():
   assert canonical == new, "canonical translation is not stable"
 
 @pytest.mark.skipif(shutil.which("gvpr") is None, reason="GVPR not available")
-@pytest.mark.xfail(strict=True)
 def test_2211():
   """
   GVPR’s `index` function should return correct results