Avoid crashes on TTY frames with over-long compositions

Eli-Zaretskii · Eli-Zaretskii · commit 16fed05ba85c · 2020-04-28T11:57:16.000+03:00
* src/term.c (encode_terminal_code): Each character from an
automatic composition is a multibyte character, so its multibyte
representation can take up to MAX_MULTIBYTE_LENGTH bytes.
Account for that when allocating storage for characters to be
encoded.  (Bug#40913)
diff --git a/src/term.c b/src/term.c
@@ -563,8 +563,8 @@ encode_terminal_code (struct glyph *src, int src_len,
 	    {
 	      cmp = composition_table[src->u.cmp.id];
 	      required = cmp->glyph_len;
-	      required *= MAX_MULTIBYTE_LENGTH;
 	    }
+	  required *= MAX_MULTIBYTE_LENGTH;
 
 	  if (encode_terminal_src_size - nbytes < required)
 	    {

Original file line number	Diff line number	Diff line change
`@@ -563,8 +563,8 @@ encode_terminal_code (struct glyph *src, int src_len,`
`563`	`563`	`{`
`564`	`564`	`cmp = composition_table[src->u.cmp.id];`
`565`	`565`	`required = cmp->glyph_len;`
`566`		`- required *= MAX_MULTIBYTE_LENGTH;`
`567`	`566`	`}`
	`567`	`+ required *= MAX_MULTIBYTE_LENGTH;`
`568`	`568`
`569`	`569`	`if (encode_terminal_src_size - nbytes < required)`
`570`	`570`	`{`