From 7ca7c3c0f927b91dad3a5b2d185fe79d12872b6d Mon Sep 17 00:00:00 2001 From: Heinrich Schuchardt Date: Sun, 29 Apr 2018 16:24:25 +0200 Subject: [PATCH] efi_loader: updating the cursor position The current coding advances the column by the number of UTF-8 bytes. The column should be increased by one per unicode character. The UEFI spec provides advance rules for U+0000, U+0008, U+000A, and U000D. All other characters, including control characters U+0007 (bel) and U+0009 (tab), have to increase the column by one. Signed-off-by: Heinrich Schuchardt Signed-off-by: Alexander Graf --- lib/efi_loader/efi_console.c | 27 +++++++++++++++++++-------- 1 file changed, 19 insertions(+), 8 deletions(-) diff --git a/lib/efi_loader/efi_console.c b/lib/efi_loader/efi_console.c index d777db8a3e..10fb224901 100644 --- a/lib/efi_loader/efi_console.c +++ b/lib/efi_loader/efi_console.c @@ -116,25 +116,36 @@ static efi_status_t EFIAPI efi_cout_output_string( unsigned int n16 = utf16_strlen(string); char buf[MAX_UTF8_PER_UTF16 * n16 + 1]; - char *p; + u16 *p; *utf16_to_utf8((u8 *)buf, string, n16) = '\0'; fputs(stdout, buf); - for (p = buf; *p; p++) { + /* + * Update the cursor position. + * + * The UEFI spec provides advance rules for U+0000, U+0008, U+000A, + * and U000D. All other characters, including control characters + * U+0007 (bel) and U+0009 (tab), have to increase the column by one. + */ + for (p = string; *p; ++p) { switch (*p) { - case '\r': /* carriage-return */ - con->cursor_column = 0; + case '\b': /* U+0008, backspace */ + con->cursor_column = max(0, con->cursor_column - 1); break; - case '\n': /* newline */ + case '\n': /* U+000A, newline */ con->cursor_column = 0; con->cursor_row++; break; - case '\t': /* tab, assume 8 char align */ + case '\r': /* U+000D, carriage-return */ + con->cursor_column = 0; break; - case '\b': /* backspace */ - con->cursor_column = max(0, con->cursor_column - 1); + case 0xd800 ... 0xdbff: + /* + * Ignore high surrogates, we do not want to count a + * Unicode character twice. + */ break; default: con->cursor_column++; -- 2.39.2