gbranden pushed a commit to branch master
in repository groff.
commit 22f5b0512b6983843aac72bd92426fcbc182bc8b
Author: G. Branden Robinson <[email protected]>
AuthorDate: Fri Apr 4 02:38:07 2025 -0500
[troff]: Slightly refactor to clarify logic.
...in difficult adjustment cases.
* src/roff/troff/env.cpp (distribute_space): Promote return type from
`void` to `bool`, communicating whether this function successfully
adjusted spaces. Add/update `return` statements.
(environment::possibly_break_line): Populate `output_width` variable
in stages, adding `extra_space` only if the `distribute_space()` call
was successful. Annotate early scenario return for comprehensibility.
(environment::wrap_up_field): Cast return value of
`distribute_space()` to `void`; since that's what was happening
implicitly before, this is a trivial type-correctness change.
This change might finally solve the mystery of Savannah #44018.
---
ChangeLog | 18 ++++++++++++++++++
src/roff/troff/env.cpp | 29 +++++++++++++----------------
2 files changed, 31 insertions(+), 16 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 49824cae8..deaeddb76 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,21 @@
+2025-04-04 G. Branden Robinson <[email protected]>
+
+ [troff]: Slightly refactor to clarify adjustment logic in
+ difficult cases.
+
+ * src/roff/troff/env.cpp (distribute_space): Promote return type
+ from `void` to `bool`, communicating whether this function
+ successfully adjusted spaces. Add/update `return` statements.
+ (environment::possibly_break_line): Populate `output_width`
+ variable in stages, adding `extra_space` only if the
+ `distribute_space()` call was successful. Annotate early
+ scenario return for comprehensibility.
+ (environment::wrap_up_field): Cast return value of
+ `distribute_space()` to `void`; since that's what was happening
+ implicitly before, this is a trivial type-correctness change.
+
+ This change might finally solve the mystery of Savannah #44018.
+
2025-04-03 G. Branden Robinson <[email protected]>
* src/roff/troff/env.cpp (environment::possibly_break_line):
diff --git a/src/roff/troff/env.cpp b/src/roff/troff/env.cpp
index 9fefd2337..a00058bcb 100644
--- a/src/roff/troff/env.cpp
+++ b/src/roff/troff/env.cpp
@@ -2189,12 +2189,12 @@ static node *node_list_reverse(node *nd)
return res;
}
-static void distribute_space(node *nd, int nspaces,
+static bool distribute_space(node *nd, int nspaces,
hunits desired_space,
bool force_reverse_node_list = false)
{
if (desired_space.is_zero() || nspaces == 0)
- return;
+ return false;
if (desired_space < H0) {
// TODO: Implement shrinkable/squeezable space adjustments here.
if (nspaces == 0)
@@ -2204,7 +2204,7 @@ static void distribute_space(node *nd, int nspaces,
else
output_warning(WARN_BREAK, "cannot adjust line; overset by %1"
" units", abs(desired_space.to_units()));
- return;
+ return false;
}
// Positive desired space is the typical case. Negative desired space
// is possible if we have overrun an unbreakable line. But we should
@@ -2234,6 +2234,7 @@ static void distribute_space(node *nd, int nspaces,
(void)node_list_reverse(nd);
if (!force_reverse_node_list)
do_reverse_node_list = !do_reverse_node_list;
+ return true;
}
void environment::possibly_break_line(bool must_break_here,
@@ -2289,16 +2290,12 @@ void environment::possibly_break_line(bool
must_break_here,
default:
assert(0 == "unhandled case of `adjust_mode`");
}
- distribute_space(pre, bp->nspaces, extra_space);
- hunits output_width = bp->width + extra_space;
- // This should become an assert() when we can get reliable width
- // data from CJK glyphs. See Savannah #44018.
- if (output_width <= 0) {
- double output_width_in_ems = output_width.to_units();
- output_warning(WARN_BREAK, "line has non-positive width %1m",
- output_width_in_ems);
+ hunits output_width = bp->width; // 0 if no breakpoint is found.
+ if (distribute_space(pre, bp->nspaces, extra_space))
+ output_width += extra_space;
+ // If we had an unbreakable, overset line, we can do no more.
+ if (output_width <= 0)
return;
- }
input_line_start -= output_width;
if (bp->hyphenated)
hyphen_line_count++;
@@ -3153,14 +3150,14 @@ void environment::wrap_up_field()
tab_field_spaces,
field_spaces + tab_field_spaces);
padding -= tab_padding;
- distribute_space(tab_contents, tab_field_spaces, tab_padding,
- true /* force reversal of node list */);
+ (void) distribute_space(tab_contents, tab_field_spaces, tab_padding,
+ true /* force reversal of node list */);
tab_field_spaces = 0;
tab_width += tab_padding;
}
if (field_spaces != 0) {
- distribute_space(line, field_spaces, padding,
- true /* force reversal of node list */);
+ (void) distribute_space(line, field_spaces, padding,
+ true /* force reversal of node list */);
width_total += padding;
if (current_tab != TAB_NONE) {
// the start of the tab has been moved to the right by padding, so
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