Standalone info viewer parses some index entries incorrectly

[ThomB]

Hello there.

There is a bug in the standalone info viewer (v7.3) where index entries can be
parsed incorrectly if the target node is del-quoted. You can see this by
issuing, for example:

        info texi2any_internals --index-search xml_accent

You should see a message that the node wasn't found.

It seems to be because DEL is not considered when reading the index entry label
in `scan_reference_label()` in info/scan.c, causing the scan to continue past
it. In the example above the label becomes:

        "xml_accent: ^?Texinfo::Convert:"

and so the target node then becomes:

      "Converter Conversion to XML^?"

instead of the label correctly being read as "xml_accent" and the rest as the
node name.

I solved this locally by including '\177' in the delimiter string in the call to
`strcspn()` at info/scan.c:1154.

I am not familiar with the rest of the codebase so I'm not sure if this would be
the right way to fix it. Nevertheless I'll attempt to attach two diffs you can
use if you'd like; one has the described fix, the other adds a test that checks
that an index entry with a del-quoted target node is split correctly.

Thomas.







diff --git a/info/Makefile.am b/info/Makefile.am
index 468f19b33a..94c97f4242 100644
--- a/info/Makefile.am
+++ b/info/Makefile.am
@@ -206,6 +206,7 @@ info_tests = \
 	t/spec-menu.sh \
 	t/empty.sh \
 	t/index-paren.sh \
+	t/quoted-index-target.sh \
 	t/help.sh
 
 TESTS = $(info_tests)
diff --git a/info/t/infodir/quoting.info b/info/t/infodir/quoting.info
index 39347b636f..f463edf3d1 100644
--- a/info/t/infodir/quoting.info
+++ b/info/t/infodir/quoting.info
@@ -11,9 +11,21 @@ File: quoting.info,  Node: Top,  Next: Colon::in, name,
 File: quoting.info, Node: Colon::in, name
 
 *Note (intera)Node 1::
+
 
+File: quoting.info, Node: Index
+
+[index]
+
+* Menu:
+
+* Colon::in, name: Colon::in, name
+
+
+
 Tag Table:
 Node: Top0
 Node: Colon::in, name256
+Node: Index327
 
 End Tag Table
diff --git a/info/t/quoted-index-target.sh b/info/t/quoted-index-target.sh
new file mode 100755
index 0000000000..a364cce357
--- /dev/null
+++ b/info/t/quoted-index-target.sh
@@ -0,0 +1,31 @@
+#!/bin/sh
+# Copyright (C) 2014-2026 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+srcdir=${srcdir:-.}
+. $srcdir/t/Init-test.inc
+
+# Perform an index search for a quoted target
+$ginfo --file quoting --index-search "Colon::in, name" --all >$ginfo_output
+
+# Test that the found index entry has the correct node name. An index entry
+# split in the wrong place should not match this RE, rather be shaped something
+# like "* Colon::in, name: ^?Colon::      in.     (line 0)"
+grep '\* Colon::in, name:[[:blank:]]\{1,\}Colon::in, name' $ginfo_output
+
+retval=$?
+
+cleanup
+

diff --git a/info/scan.c b/info/scan.c
index 1b01ab5220..24ef0df310 100644
--- a/info/scan.c
+++ b/info/scan.c
@@ -1151,7 +1151,7 @@ scan_reference_label (REFERENCE *entry, int in_index)
 
       while (1)
         {
-          n = strcspn (p, ":\n");
+          n = strcspn (p, "\177:\n");
           if (p[n] == ':')
             {
               m += n + 1;