[epiphany/mwleeds/webapp-dbus-api: 65/69] Fix ephy_string_find_and_replace

[Phaedrus Leeds <mwleeds src gnome org>]

commit 8df5b9d215118a25ee3743e4a209199cd5ab6ce2
Author: Phaedrus Leeds <mwleeds protonmail com>
Date:   Mon Jan 24 19:36:28 2022 -0800

    Fix ephy_string_find_and_replace
    
    This replaces the implementation with the one from GLib
    g_string_replace() because I thought it might help a bug I was seeing.
    It doesn't help; the bug was elsewhere. But it still seems like a good
    idea to do this.

 lib/ephy-string.c | 28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)
---
diff --git a/lib/ephy-string.c b/lib/ephy-string.c
index dd434e1b8..1606a5af0 100644
--- a/lib/ephy-string.c
+++ b/lib/ephy-string.c
@@ -244,8 +244,9 @@ ephy_string_find_and_replace (const char *haystack,
                               const char *to_repl)
 {
   GString *str;
-  const char *tmp;
+  gchar *cur, *next;
   gsize to_find_len;
+  gsize to_repl_len;
   gsize pos;
 
   g_assert (haystack);
@@ -254,12 +255,25 @@ ephy_string_find_and_replace (const char *haystack,
 
   str = g_string_new (haystack);
   to_find_len = strlen (to_find);
-
-  while ((tmp = strstr (str->str, to_find)) != NULL) {
-    pos = tmp - str->str;
-    g_string_erase (str, pos, to_find_len);
-    g_string_insert (str, pos, to_repl);
-  }
+  to_repl_len = strlen (to_repl);
+  cur = str->str;
+
+  while ((next = strstr (cur, to_find)) != NULL)
+    {
+      pos = next - str->str;
+      g_string_erase (str, pos, to_find_len);
+      g_string_insert (str, pos, to_repl);
+      cur = str->str + pos + to_repl_len;
+      /* Only match the empty string once at any given position, to
+       * avoid infinite loops */
+      if (to_find_len == 0)
+        {
+          if (cur[0] == '\0')
+            break;
+          else
+            cur++;
+        }
+    }
 
   return g_string_free (str, FALSE);
 }