Remove DA3 from queries emitted by term_put_level_2_queries()

See the added comment for why.

Most terminals that reply to DA3 also reply to another query producing
the same result and/or don't respond to `TFLAG_QUERY_L3` queries anyway.

src/terminal/output.c

@@ -240,7 +240,6 @@ void term_put_level_2_queries(Terminal *term, bool emit_all)
     static const char queries[] =
         "\033[>0q" // XTVERSION (terminal name and version)
         "\033[>c" // DA2 (Secondary Device Attributes)
-        "\033[=c" // DA3 (Tertiary Device Attributes)
         "\033[?u" // Kitty keyboard protocol flags
         "\033[?1036$p" // DECRQM 1036 (metaSendsEscape; must be after kitty query)
         "\033[?1039$p" // DECRQM 1039 (altSendsEscape; must be after kitty query)

src/terminal/query.c

@@ -324,6 +324,11 @@ KeyCode parse_dcs_query_reply(const char *data, size_t len, bool truncated)
     // https://vt100.net/docs/vt510-rm/DA3.html
     // https://invisible-island.net/xterm/ctlseqs/ctlseqs.html#:~:text=(-,Tertiary%20DA,-)
     if (strview_remove_matching_prefix(&seq, "!|")) {
+        // Note that DA3 is no longer sent by term_put_level_2_queries(),
+        // because several terminals (including Termux) have buggy handling
+        // of CSI sequences containing '=', which causes "c" to be rendered
+        // (but not inserted into the buffer) at startup.
+        // See also: https://github.com/fish-shell/fish-shell/commit/e49dde87cc0f1dcedd424d5ed7a520a3f011ee29
         LOG_INFO("DA3 reply: %.*s", (int)seq.length, seq.data);
         return tflag(TFLAG_QUERY_L3);
     }

test/terminal.c

@@ -1700,7 +1700,6 @@ static void test_term_put_level_1_queries(TestContext *ctx)
         // term_put_level_2_queries()
         "\033[>0q"
         "\033[>c"
-        "\033[=c"
         "\033[?u"
         "\033[?1036$p"
         "\033[?1039$p"