diff options
| -rw-r--r-- | src/ChangeLog | 19 | ||||
| -rw-r--r-- | src/bidi.c | 59 |
2 files changed, 68 insertions, 10 deletions
diff --git a/src/ChangeLog b/src/ChangeLog index 07b0418b399..d21e6383764 100644 --- a/src/ChangeLog +++ b/src/ChangeLog @@ -1,3 +1,22 @@ +2011-10-18 Eli Zaretskii <eliz@gnu.org> + + Fix part 3 of bug#9771. + * bidi.c (bidi_line_init): Initialize next_en_pos to zero, not -1. + (bidi_resolve_neutral): Don't enter the expensive loop looking for + non-neutral characters if the current character is a paragraph + separator (a.k.a. Newline). This avoids running the same + expensive loop twice, once when we consume the preceding newline + and the other time when the line actually needs to be displayed. + Avoid the loop when we see neutrals on the base embedding level + following a character whose directionality is the same as the + paragraph's. This avoids running the expensive loop when a line + ends in a long sequence of neutrals, like control characters. + Add assertion against STRONG_AL type. Slightly rearrange code + that determines the type of a neutral given the first non-neutral + that follows it. + (bidi_level_of_next_char): Set next_en_pos to zero when + invalidating its info. + 2011-10-17 Eli Zaretskii <eliz@gnu.org> * xdisp.c (push_display_prop): Determine whether to record string diff --git a/src/bidi.c b/src/bidi.c index f06c146ca84..29e3c817318 100644 --- a/src/bidi.c +++ b/src/bidi.c @@ -846,7 +846,9 @@ bidi_line_init (struct bidi_it *bidi_it) bidi_it->level_stack[0].override = NEUTRAL_DIR; /* X1 */ bidi_it->invalid_levels = 0; bidi_it->invalid_rl_levels = -1; - bidi_it->next_en_pos = -1; + /* Setting this to zero will force its recomputation the first time + we need it for W5. */ + bidi_it->next_en_pos = 0; bidi_it->next_for_ws.type = UNKNOWN_BT; bidi_set_sor_type (bidi_it, (bidi_it->paragraph_dir == R2L ? 1 : 0), @@ -1732,7 +1734,7 @@ bidi_resolve_weak (struct bidi_it *bidi_it) if (bidi_it->prev.type_after_w1 == WEAK_EN /* ET/BN w/EN before it */ || bidi_it->next_en_pos > bidi_it->charpos) type = WEAK_EN; - else /* W5: ET/BN with EN after it. */ + else if (bidi_it->next_en_pos >=0) /* W5: ET/BN with EN after it. */ { EMACS_INT en_pos = bidi_it->charpos + bidi_it->nchars; const unsigned char *s = (STRINGP (bidi_it->string.lstring) @@ -1775,6 +1777,11 @@ bidi_resolve_weak (struct bidi_it *bidi_it) else if (type == WEAK_BN) type = NEUTRAL_ON; /* W6/Retaining */ } + else if (type_of_next == NEUTRAL_B) + /* Record the fact that there are no more ENs from + here to the end of paragraph, to avoid entering the + loop above ever again in this paragraph. */ + bidi_it->next_en_pos = -1; } } } @@ -1843,13 +1850,45 @@ bidi_resolve_neutral (struct bidi_it *bidi_it) || type == NEUTRAL_ON)) abort (); - if (bidi_get_category (type) == NEUTRAL + if ((type != NEUTRAL_B /* Don't risk entering the long loop below if + we are already at paragraph end. */ + && bidi_get_category (type) == NEUTRAL) || (type == WEAK_BN && prev_level == current_level)) { if (bidi_it->next_for_neutral.type != UNKNOWN_BT) type = bidi_resolve_neutral_1 (bidi_it->prev_for_neutral.type, bidi_it->next_for_neutral.type, current_level); + /* The next two "else if" clauses are shortcuts for the + important special case when we have a long sequence of + neutral or WEAK_BN characters, such as whitespace or nulls or + other control characters, on the base embedding level of the + paragraph, and that sequence goes all the way to the end of + the paragraph and follows a character whose resolved + directionality is identical to the base embedding level. + (This is what happens in a buffer with plain L2R text that + happens to include long sequences of control characters.) By + virtue of N1, the result of examining this long sequence will + always be either STRONG_L or STRONG_R, depending on the base + embedding level. So we use this fact directly instead of + entering the expensive loop in the "else" clause. */ + else if (current_level == 0 + && bidi_it->prev_for_neutral.type == STRONG_L + && !bidi_explicit_dir_char (bidi_it->ch)) + type = bidi_resolve_neutral_1 (bidi_it->prev_for_neutral.type, + STRONG_L, current_level); + else if (/* current level is 1 */ + current_level == 1 + /* base embedding level is also 1 */ + && bidi_it->level_stack[0].level == 1 + /* previous character is one of those considered R for + the purposes of W5 */ + && (bidi_it->prev_for_neutral.type == STRONG_R + || bidi_it->prev_for_neutral.type == WEAK_EN + || bidi_it->prev_for_neutral.type == WEAK_AN) + && !bidi_explicit_dir_char (bidi_it->ch)) + type = bidi_resolve_neutral_1 (bidi_it->prev_for_neutral.type, + STRONG_R, current_level); else { /* Arrrgh!! The UAX#9 algorithm is too deeply entrenched in @@ -1900,6 +1939,9 @@ bidi_resolve_neutral (struct bidi_it *bidi_it) case STRONG_L: case STRONG_R: case STRONG_AL: + /* Actually, STRONG_AL cannot happen here, because + bidi_resolve_weak converts it to STRONG_R, per W3. */ + xassert (type != STRONG_AL); next_type = type; break; case WEAK_EN: @@ -1907,7 +1949,6 @@ bidi_resolve_neutral (struct bidi_it *bidi_it) /* N1: ``European and Arabic numbers are treated as though they were R.'' */ next_type = STRONG_R; - saved_it.next_for_neutral.type = STRONG_R; break; case WEAK_BN: if (!bidi_explicit_dir_char (bidi_it->ch)) @@ -1920,11 +1961,7 @@ bidi_resolve_neutral (struct bidi_it *bidi_it) member. */ if (saved_it.type != WEAK_BN || bidi_get_category (bidi_it->prev.type_after_w1) == NEUTRAL) - { - next_type = bidi_it->prev_for_neutral.type; - saved_it.next_for_neutral.type = next_type; - bidi_check_type (next_type); - } + next_type = bidi_it->prev_for_neutral.type; else { /* This is a BN which does not adjoin neutrals. @@ -1938,7 +1975,9 @@ bidi_resolve_neutral (struct bidi_it *bidi_it) } type = bidi_resolve_neutral_1 (saved_it.prev_for_neutral.type, next_type, current_level); + saved_it.next_for_neutral.type = next_type; saved_it.type = type; + bidi_check_type (next_type); bidi_check_type (type); bidi_copy_it (bidi_it, &saved_it); } @@ -2014,7 +2053,7 @@ bidi_level_of_next_char (struct bidi_it *bidi_it) bidi_it->next_for_neutral.type = UNKNOWN_BT; if (bidi_it->next_en_pos >= 0 && bidi_it->charpos >= bidi_it->next_en_pos) - bidi_it->next_en_pos = -1; + bidi_it->next_en_pos = 0; if (bidi_it->next_for_ws.type != UNKNOWN_BT && bidi_it->charpos >= bidi_it->next_for_ws.charpos) bidi_it->next_for_ws.type = UNKNOWN_BT; |