Fix and test cases for Mantis bug 1839 (and 2012)

README.md

@@ -1,6 +1,6 @@
 # Inform 7
 
-v10.1.0-alpha.1+6U78 'Krypton' (9 April 2022)
+v10.1.0-alpha.1+6U79 'Krypton' (10 April 2022)
 
 ## About Inform 7
 

build.txt

@@ -1,3 +1,3 @@
 Prerelease: alpha.1
-Build Date: 9 April 2022
-Build Number: 6U78
+Build Date: 10 April 2022
+Build Number: 6U79

inform7/Tests/Test Problems/PM_FigureWhiteSpace.txt

@@ -0,0 +1,4 @@
+There is room.
+
+Figure null is the file "".
+Figure nearly null is the file "  ".

inform7/Tests/Test Problems/PM_SoundWhiteSpace.txt

@@ -0,0 +1,4 @@
+There is room.
+
+Sound null is the file "".
+Sound nearly null is the file " ".

inform7/Tests/Test Problems/_Results_Ideal/PM_FigureWhiteSpace.txt

@@ -0,0 +1,13 @@
+Inform 7 v10.1.0 has started.
+I've now read your source text, which is 14 words long.
+I've also read Basic Inform by Graham Nelson, which is 7691 words long.
+I've also read English Language by Graham Nelson, which is 2328 words long.
+I've also read Standard Rules by Graham Nelson, which is 32092 words long.
+Problem__ PM_FigureWhiteSpace
+  >--> You wrote 'Figure null is the file ""' (source text, line 3): but this
+    is not a filename I can use, because it is either empty or contains only
+    spaces.
+Problem__ PM_FigureWhiteSpace
+  >--> You wrote 'Figure nearly null is the file " "' (source text, line 4):
+    again, this is not a filename I can use.
+Inform 7 has finished.

inform7/Tests/Test Problems/_Results_Ideal/PM_SoundWhiteSpace.txt

@@ -0,0 +1,13 @@
+Inform 7 v10.1.0 has started.
+I've now read your source text, which is 14 words long.
+I've also read Basic Inform by Graham Nelson, which is 7691 words long.
+I've also read English Language by Graham Nelson, which is 2328 words long.
+I've also read Standard Rules by Graham Nelson, which is 32092 words long.
+Problem__ PM_SoundWhiteSpace
+  >--> You wrote 'Sound null is the file ""' (source text, line 3): but this is
+    not a filename I can use, because it is either empty or contains only
+    spaces.
+Problem__ PM_SoundWhiteSpace
+  >--> You wrote 'Sound nearly null is the file " "' (source text, line 4):
+    again, this is not a filename I can use.
+Inform 7 has finished.

inform7/multimedia-module/Chapter 2/Figures.w

@@ -103,9 +103,15 @@ void Figures::register_figure(wording W, wording FN) {
 		if (wn >= 0) id = Task::get_next_free_blorb_resource_ID();
 		TEMPORARY_TEXT(leaf)
 		WRITE_TO(leaf, "%N", wn);
-		DISCARD_TEXT(leaf)
+		if ((wn >= 0) && (Str::is_whitespace(leaf))) {
+			StandardProblems::sentence_problem(Task::syntax_tree(), _p_(PM_FigureWhiteSpace),
+				"this is not a filename I can use",
+				"because it is either empty or contains only spaces.");
+			return;
+		}
 		filename *figure_file = NULL;
 		if (wn >= 0) figure_file = Filenames::in(Task::figures_path(), leaf);
+		DISCARD_TEXT(leaf)
 		Figures::figures_create(W, id, figure_file, <<alttext>>);
 		LOGIF(MULTIMEDIA_CREATIONS, "Created figure <%W> = filename '%f' = resource ID %d\n",
 			W, figure_file, id);

inform7/multimedia-module/Chapter 2/Sound Effects.w

@@ -96,8 +96,14 @@ void Sounds::register_sound(wording W, wording FN) {
 		int id = Task::get_next_free_blorb_resource_ID();
 		TEMPORARY_TEXT(leaf)
 		WRITE_TO(leaf, "%N", wn);
-		DISCARD_TEXT(leaf)
+		if (Str::is_whitespace(leaf)) {
+			StandardProblems::sentence_problem(Task::syntax_tree(), _p_(PM_SoundWhiteSpace),
+				"this is not a filename I can use",
+				"because it is either empty or contains only spaces.");
+			return;
+		}
 		filename *sound_file = Filenames::in(Task::sounds_path(), leaf);
+		DISCARD_TEXT(leaf)
 		Sounds::sounds_create(W, id, sound_file, <<alttext>>);
 		LOGIF(MULTIMEDIA_CREATIONS,
 			"Created sound effect <%W> = filename '%N' = resource ID %d\n", W, wn, id);