shithub: rgbds

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Fix dead stores in `charmap_ConvertNext`

Also cleanup / rearrange some of the function while we're at it.

--- a/src/asm/charmap.c

+++ b/src/asm/charmap.c

@@ -215,31 +215,34 @@

 	size_t rewindDistance = 0;

 	for (;;) {

-		/* We still want NULs to reach the `else` path, to give a chance to rewind */

 		uint8_t c = **input - 1;

 		if (**input && node->next[c]) {

-			(*input)++; /* Consume that char */

+			// Consume that char

+			(*input)++;

 			rewindDistance++;

+			// Advance to next node (index starts at 1)

 			node = &charmap->nodes[node->next[c]];

 			if (node->isTerminal) {

+				// This node matches, register it

 				match = node;

-				rewindDistance = 0; /* Rewind from after the match */

+				rewindDistance = 0; // If no longer match is found, rewind here

 			}

 		} else {

-			*input -= rewindDistance; /* Rewind */

-			rewindDistance = 0;

-			node = &charmap->nodes[0];

+			// We are at a dead end (either because we reached the end of input, or of

+			// the trie), so rewind up to the last match, and output.

+			*input -= rewindDistance; // This will rewind all the way if no match found

-			if (match) { /* Arrived at a dead end with a match found */

+			if (match) { // A match was found, use it

 				if (output)

 					*(*output)++ = match->value;

 				return 1;

-			} else if (**input) { /* No match found */

+			} else if (**input) { // No match found, but there is some input left

+				// This will write the codepoint's value to `output`, little-endian

 				size_t codepointLen = readUTF8Char(output ? *output : NULL,

 								   *input);

@@ -246,7 +249,7 @@

 				if (codepointLen == 0)

 					error("Input string is not valid UTF-8!\n");

-				/* OK because UTF-8 has no NUL in multi-byte chars */

+				// OK because UTF-8 has no NUL in multi-byte chars

 				*input += codepointLen;

 				if (output)

 					*output += codepointLen;

@@ -253,11 +256,9 @@

 				return codepointLen;

-			} else { /* End of input */

+			} else { // End of input

 				return 0;

 			}

 		}

 	}

-

-	unreachable_();

 }