From e46352bc614cf9777ca76deb47330fb408bc1a23 Mon Sep 17 00:00:00 2001
From: Robin Haberkorn <robin.haberkorn@googlemail.com>
Date: Sat, 2 Aug 2025 13:16:16 +0300
Subject: fixed serious bug with certain alternative string termination chars
 in commands with multiple string arguments
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* When `@`-modifying a command with several string arguments and choosing `{` as the alternative
  string termination character, the parser would get totally confused.
  Any sequence of `{` would be ignored and only the first non-`{` would become the termination character.
  Consequently you also couldn't choose a new terminator after the closing `}`.
  So even a documented code example from sciteco(7) wouldn't work.
  The same was true when using $ (escape) or ^A as the alternative termination character.
* We can now correctly parse e.g. `@FR{foo}{bar}` or `@FR$foo$bar$` (even though the
  latter one is quite pointless).
* has probably been broken forever (has been broken even before v2.0).
* Whitespace is now ignored in front of alternative termination characters as in TECO-64, so
  we can also write `@S /foo/` or even
  ```
  @^Um
  {
    !* blabla *!
  }
  ```
  I wanted to disallow whitespace termination characters, so the alternative would have been
  to throw an error.
  The new implementation at least adds some functionality.
  * Avoid redundancies when parsing no-op characters via teco_is_noop().
    I assume that this is inlined and drawn into any jump-table what would be
    generated for the switch-statement in teco_state_start_input().
 * Alternative termination characters are still case-folded, even if they are Unicode glyphs,
   so `@IЖfooж` would work and insert `foo`.
   This should perhaps be restricted to ANSI characters?
---
 tests/testsuite.at | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'tests/testsuite.at')

diff --git a/tests/testsuite.at b/tests/testsuite.at
index 428757c..15fb810 100644
--- a/tests/testsuite.at
+++ b/tests/testsuite.at
@@ -118,6 +118,9 @@ AT_SETUP([String arguments])
 TE_CHECK([[Ifoo^Q]]TE_ESCAPE[[(0/0)]]TE_ESCAPE, 0, ignore, ignore)
 TE_CHECK([[@I"foo^Q"(0/0)"]], 0, ignore, ignore)
 TE_CHECK([[@I{foo{bar}foo^Q{(0/0)}]], 0, ignore, ignore)
+TE_CHECK([[@^Ua
+           {12345} :Qa-5"N(0/0)']], 0, ignore, ignore)
+TE_CHECK([[@I/X/ H@FR{X}/12345/ Z-5"N(0/0)']], 0, ignore, ignore)
 TE_CHECK([[@Ia^EQa(0/0)a]], 0, ignore, ignore)
 # Video-TECO-like syntax - might change in the future
 TE_CHECK([[@I/^E<65>^E<0x41>^E<0101>/ <-A:; -A-^^A"N(0/0)' R>]], 0, ignore, ignore)
-- 
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