Minor issue saving '\' in keymap in nightlies

[Max Stats]

I have encountered a very minor issue in the nightlies. I have a keymap for '^\', and when I save keymaps, the next time I load the game I receive an error that the line in the pref file with this keymap is too long. I assume that this is because the '\' character escapes the newline after it, and this messes everything up. I can fix it by editing the pref file and changing the trigger to '^\\'. This fixes it until the next time I save keymaps.

The fix seems to be writing two '\' characters anytime one is encountered in a keymap. I don't care too much, because once I get my keymaps set, I won't be saving them much anymore.

[myshkin]

Confirmed, and entered as bug 1389 on trac. Thanks for the report.

[Max Stats]

For awhile, I thought that once I had my keymaps set, I wouldn't need to change them much, and this bug wouldn't be that annoying. Turns out, it is more annoying than I thought, as I still tweak my keymaps from time to time. In fact, it was annoying enough that I decided to take a swing at it and see if I could fix it on my copy. I think I have done it. Here is my patch:

diff --git a/src/keymap.c b/src/keymap.c
index 35a3304..d1a0818 100644
--- a/src/keymap.c
+++ b/src/keymap.c
@@ -174,12 +174,12 @@ void keymap_dump(ang_file *fff)
 		struct keypress key[2] = { { 0 }, { 0 } };
 
 		/* Encode the action */
-		keypress_to_text(buf, sizeof(buf), k->actions);
+		keypress_to_text(buf, sizeof(buf), k->actions, FALSE);
 		file_putf(fff, "A:%s\n", buf);
 
 		/* Convert the key into a string */
 		key[0] = k->key;
-		keypress_to_text(buf, sizeof(buf), key);
+		keypress_to_text(buf, sizeof(buf), key, TRUE);
 		file_putf(fff, "C:%d:%s\n", mode, buf);
 
 		file_putf(fff, "\n");
diff --git a/src/ui-event.c b/src/ui-event.c
index c9e9601..44412ef 100644
--- a/src/ui-event.c
+++ b/src/ui-event.c
@@ -221,7 +221,7 @@ void keypress_from_text(struct keypress *buf, size_t len, const char *str)
 /*
  * Convert a string of keypresses into their textual equivalent.
  */
-void keypress_to_text(char *buf, size_t len, const struct keypress *src)
+void keypress_to_text(char *buf, size_t len, const struct keypress *src, bool expand_backslash)
 {
 	size_t cur = 0;
 	size_t end = 0;
@@ -258,7 +258,13 @@ void keypress_to_text(char *buf, size_t len, const struct keypress *src)
 		} else {
 			switch (i) {
 				case '\a': strnfcat(buf, len, &end, "\a"); break;
-				case '\\': strnfcat(buf, len, &end, "\\"); break;
+				case '\\': {
+					if (expand_backslash)
+						   strnfcat(buf, len, &end, "\\\\");
+					else
+						   strnfcat(buf, len, &end, "\\");
+					break;
+				}
 				case '^': strnfcat(buf, len, &end, "\\^"); break;
 				case '[': strnfcat(buf, len, &end, "\\["); break;
 				default: {
diff --git a/src/ui-event.h b/src/ui-event.h
index 5becb8e..0942fe5 100644
--- a/src/ui-event.h
+++ b/src/ui-event.h
@@ -179,7 +179,7 @@ keycode_t keycode_find_code(const char *str, size_t len);
 const char *keycode_find_desc(keycode_t kc);
 
 /** Convert a string of keypresses into their textual representation */
-void keypress_to_text(char *buf, size_t len, const struct keypress *src);
+void keypress_to_text(char *buf, size_t len, const struct keypress *src, bool expand_backslash);
 
 /** Covert a textual representation of keypresses into actual keypresses */
 void keypress_from_text(struct keypress *buf, size_t len, const char *str);
diff --git a/src/ui-options.c b/src/ui-options.c
index ce5a849..7bc5e2a 100644
--- a/src/ui-options.c
+++ b/src/ui-options.c
@@ -367,7 +367,7 @@ static struct keypress keymap_get_trigger(void)
 	buf[0] = inkey();
 
 	/* Convert to ascii */
-	keypress_to_text(tmp, sizeof(tmp), buf);
+	keypress_to_text(tmp, sizeof(tmp), buf, FALSE);
 
 	/* Hack -- display the trigger */
 	Term_addstr(-1, TERM_WHITE, tmp);
@@ -420,7 +420,7 @@ static void ui_keymap_query(const char *title, int row)
 	else
 	{
 		/* Analyze the current action */
-		keypress_to_text(tmp, sizeof(tmp), act);
+		keypress_to_text(tmp, sizeof(tmp), act, FALSE);
 	
 		/* Display the current action */
 		prt("Found: ", 15, 0);
@@ -449,7 +449,7 @@ static void ui_keymap_create(const char *title, int row)
 	while (!done) {
 		struct keypress kp;
 
-		keypress_to_text(tmp, sizeof(tmp), keymap_buffer);
+		keypress_to_text(tmp, sizeof(tmp), keymap_buffer, FALSE);
 		c_prt(first ? TERM_YELLOW : TERM_WHITE,
 				format("Action: %s", tmp), 15, 0);
 
@@ -515,7 +515,7 @@ static void keymap_browse_hook(int oid, void *db, const region *loc)
 
 	/* Show current action */
 	prt("Current action (if any) shown below:", 13, 0);
-	keypress_to_text(tmp, sizeof(tmp), keymap_buffer);
+	keypress_to_text(tmp, sizeof(tmp), keymap_buffer, FALSE);
 	prt(tmp, 14, 0);
 }

Caveat: I poke around the code from time to time, but I am far from familiar with it, so a more elegant solution might be possible from someone more learned than I am. The gist of this is to add a flag to keypress_to_text that causes it to double the backslash character when it is TRUE. Everyone sets the flag to FALSE except keymap_dump, which sets it to true when outputting the "C:" lines.

I have tested this on my own pref files, which seem to work correctly, but I naturally can't guarantee that this won't introduce bugs of its own.

[Magnate]

For awhile, I thought that once I had my keymaps set, I wouldn't need to change them much, and this bug wouldn't be that annoying. Turns out, it is more annoying than I thought, as I still tweak my keymaps from time to time. In fact, it was annoying enough that I decided to take a swing at it and see if I could fix it on my copy. I think I have done it. Here is my patch:

Awesome - thank you. This looks fine at first glance, but the input layer is not my specialty so I will wait for one of the others to cast an eye over it before committing.

[myshkin]

Here is my patch:

Thanks! I have committed this change to staging, and it should be in a dev release shortly. Note that the keymap module does not actually map a bare '\', as that is needed for command escaping, but your change fixes behavior for keypresses like ^\.