Merge lp:~widelands-dev/widelands/bugfix-1801208 into lp:widelands

[Arty]

Changed some types from uint to int to avoid overflows in calculations.

Forced the text anchor for drawing multiline text areas to be non-negative, so that text alignment wouldn't be based on overlong lines. (Otherwise short lines wouldn't be aligned properly, possibly even be outside the visible area.)

[bunnybot (widelandsofficial)]

Continuous integration builds have changed state:

Travis build 4206. State: errored. Details: https://travis-ci.org/widelands/widelands/builds/453338126.
Appveyor build 4002. State: failed. Details: https://ci.appveyor.com/project/widelands-dev/widelands/build/_widelands_dev_widelands_bugfix_1801208-4002.

[GunChleoc (gunchleoc)]

Code LGTM :)

@bunnybot merge

review: Approve

[bunnybot (widelandsofficial)]

Refusing to merge, since Travis is not green. Use @bunnybot merge force for merging anyways.

Travis build 4206. State: errored. Details: https://travis-ci.org/widelands/widelands/builds/453338126.

[GunChleoc (gunchleoc)]

Transient failure on Travis

@bunnybot merge force

=== modified file 'src/ui_basic/multilinetextarea.cc'
--- src/ui_basic/multilinetextarea.cc	2018-08-12 16:35:30 +0000
+++ src/ui_basic/multilinetextarea.cc	2018-11-10 17:41:58 +0000
@@ -30,7 +30,8 @@
 
 namespace UI {
 
-static const uint32_t RICHTEXT_MARGIN = 2;
+// int instead of uint because of overflow situations
+static const int32_t RICHTEXT_MARGIN = 2;
 
 MultilineTextarea::MultilineTextarea(Panel* const parent,
                                      const int32_t x,
@@ -141,11 +142,19 @@
 	int anchor = 0;
 	Align alignment = mirror_alignment(align_, text_);
 	switch (alignment) {
+	// TODO(Arty): We might want to revisit this after the font renderer can handle long strings
+	// without whitespaces differently.
+	// Currently, such long unbreakable strings are silently assumed to fit the line exactly,
+	// which means that rendered_text_->width() might actually be larger than the effective width
+	// of the textarea. If we'd allow the anchor here to become negative in this case, it would
+	// properly position the longest line (just truncated), BUT the positioning of shorter lines
+	// would be off (possibly even outside the textarea, thus invisible) because their positioning
+	// is calculated without regard for overlong lines.
 	case UI::Align::kCenter:
-		anchor = (get_eff_w() - rendered_text_->width()) / 2;
+		anchor = std::max(0, (get_eff_w() - rendered_text_->width()) / 2);
 		break;
 	case UI::Align::kRight:
-		anchor = get_eff_w() - rendered_text_->width() - RICHTEXT_MARGIN;
+		anchor = std::max(0, get_eff_w() - rendered_text_->width() - RICHTEXT_MARGIN);
 		break;
 	case UI::Align::kLeft:
 		anchor = RICHTEXT_MARGIN;
 
=== modified file 'src/ui_basic/multilinetextarea.h'
--- src/ui_basic/multilinetextarea.h	2018-07-08 09:18:33 +0000
+++ src/ui_basic/multilinetextarea.h	2018-11-10 17:41:58 +0000
@@ -60,7 +60,8 @@
 	}
 
 	void set_text(const std::string&);
-	uint32_t get_eff_w() const {
+	// int instead of uint because of overflow situations
+	int32_t get_eff_w() const {
 		return scrollbar_.is_enabled() ? get_w() - Scrollbar::kSize : get_w();
 	}