The unilbrk implementation does not implement the rules sequentially,
but uses a table and as few as possible 'if' conditions in the main
code flow, for speed. This has the effect that in some cases, the
implementation of a rule with lower priority has side effects on a
rule with higher priority.
This patch fixes this, in those cases that became apparent from
LineBreakTest.txt.
2024-09-15 Bruno Haible <br...@clisp.org>
unilbrk: Fix conflicts between rules.
* lib/unilbrk/u8-possible-linebreaks.c (u8_possible_linebreaks_loop):
Avoid side effect of (LB18) on (LB14) and (LB15a). Avoid side effect
of (LB19a) on (LB18).
* lib/unilbrk/u16-possible-linebreaks.c (u16_possible_linebreaks_loop):
Likewise.
* lib/unilbrk/u32-possible-linebreaks.c (u32_possible_linebreaks_loop):
Likewise.
diff --git a/lib/unilbrk/u16-possible-linebreaks.c
b/lib/unilbrk/u16-possible-linebreaks.c
index bf0f31057f..9678041606 100644
--- a/lib/unilbrk/u16-possible-linebreaks.c
+++ b/lib/unilbrk/u16-possible-linebreaks.c
@@ -190,7 +190,12 @@ u16_possible_linebreaks_loop (const uint16_t *s, size_t n,
const char *encoding,
last_prop = LBP_AL1;
seen_space = NULL;
}
- else if (last_prop == LBP_ZW || seen_space != NULL)
+ else if (last_prop == LBP_ZW
+ || (seen_space != NULL
+ /* (LB14) has higher priority than (LB18). */
+ && !(last_prop == LBP_OP1 || last_prop ==
LBP_OP2)
+ /* (LB15a) has higher priority than (LB18). */
+ && !(last_prop == LBP_QU2)))
{
/* (LB8) Break after zero-width space. */
/* (LB18) Break after spaces.
@@ -236,7 +241,9 @@ u16_possible_linebreaks_loop (const uint16_t *s, size_t n,
const char *encoding,
*p = UC_BREAK_POSSIBLE;
}
else if (((prop == LBP_QU1 || prop == LBP_QU2 || prop ==
LBP_QU3)
- && (! prev_ea || ! EA (lookahead1_prop_ea)))
+ && (! prev_ea || ! EA (lookahead1_prop_ea))
+ /* (LB18) has higher priority than (LB19a). */
+ && prev_prop != LBP_SP)
|| ((prev_prop == LBP_QU1 || prev_prop == LBP_QU2
|| prev_prop == LBP_QU3)
&& (! prev2_ea || ! ea)))
{
diff --git a/lib/unilbrk/u32-possible-linebreaks.c
b/lib/unilbrk/u32-possible-linebreaks.c
index a7630467a6..c12ca3abbb 100644
--- a/lib/unilbrk/u32-possible-linebreaks.c
+++ b/lib/unilbrk/u32-possible-linebreaks.c
@@ -183,7 +183,12 @@ u32_possible_linebreaks_loop (const uint32_t *s, size_t n,
const char *encoding,
last_prop = LBP_AL1;
seen_space = NULL;
}
- else if (last_prop == LBP_ZW || seen_space != NULL)
+ else if (last_prop == LBP_ZW
+ || (seen_space != NULL
+ /* (LB14) has higher priority than (LB18). */
+ && !(last_prop == LBP_OP1 || last_prop ==
LBP_OP2)
+ /* (LB15a) has higher priority than (LB18). */
+ && !(last_prop == LBP_QU2)))
{
/* (LB8) Break after zero-width space. */
/* (LB18) Break after spaces.
@@ -229,7 +234,9 @@ u32_possible_linebreaks_loop (const uint32_t *s, size_t n,
const char *encoding,
*p = UC_BREAK_POSSIBLE;
}
else if (((prop == LBP_QU1 || prop == LBP_QU2 || prop ==
LBP_QU3)
- && (! prev_ea || ! EA (lookahead1_prop_ea)))
+ && (! prev_ea || ! EA (lookahead1_prop_ea))
+ /* (LB18) has higher priority than (LB19a). */
+ && prev_prop != LBP_SP)
|| ((prev_prop == LBP_QU1 || prev_prop == LBP_QU2
|| prev_prop == LBP_QU3)
&& (! prev2_ea || ! ea)))
{
diff --git a/lib/unilbrk/u8-possible-linebreaks.c
b/lib/unilbrk/u8-possible-linebreaks.c
index 7abf20beed..3f32ee6289 100644
--- a/lib/unilbrk/u8-possible-linebreaks.c
+++ b/lib/unilbrk/u8-possible-linebreaks.c
@@ -190,7 +190,12 @@ u8_possible_linebreaks_loop (const uint8_t *s, size_t n,
const char *encoding,
last_prop = LBP_AL1;
seen_space = NULL;
}
- else if (last_prop == LBP_ZW || seen_space != NULL)
+ else if (last_prop == LBP_ZW
+ || (seen_space != NULL
+ /* (LB14) has higher priority than (LB18). */
+ && !(last_prop == LBP_OP1 || last_prop ==
LBP_OP2)
+ /* (LB15a) has higher priority than (LB18). */
+ && !(last_prop == LBP_QU2)))
{
/* (LB8) Break after zero-width space. */
/* (LB18) Break after spaces.
@@ -236,7 +241,9 @@ u8_possible_linebreaks_loop (const uint8_t *s, size_t n,
const char *encoding,
*p = UC_BREAK_POSSIBLE;
}
else if (((prop == LBP_QU1 || prop == LBP_QU2 || prop ==
LBP_QU3)
- && (! prev_ea || ! EA (lookahead1_prop_ea)))
+ && (! prev_ea || ! EA (lookahead1_prop_ea))
+ /* (LB18) has higher priority than (LB19a). */
+ && prev_prop != LBP_SP)
|| ((prev_prop == LBP_QU1 || prev_prop == LBP_QU2
|| prev_prop == LBP_QU3)
&& (! prev2_ea || ! ea)))
{
