commit 2aeddf9c1b0f33b94a01a0c307e3408b89e746c5
from: Omar Polo <op@omarpolo.com>
date: Sun Jul 18 17:34:15 2021 UTC

emit a dummy NUL byte on empty files

an empty initializer, such as

	uint8_t foo[] = { };

raises a warning: "use of GNU empty initializer extension" using
-pedantic.  This adds a dummy NUL byte that's not accounted in the len
counter.  So, now it produces:

	uint8_t foo[] = { 0x0 };
	size_t foo_len = 0;

commit - 0ce8aa3ef6cc677ab907e74becbe9fce44fbe3eb
commit + 2aeddf9c1b0f33b94a01a0c307e3408b89e746c5
blob - 0ae6f24d8ac4d26741ef8894b8152b46a69f5620
blob + 57991d3be50c6e5da66de728fe6b4435bf31bbb7
--- pagebundler.c
+++ pagebundler.c
@@ -35,7 +35,7 @@ int
 main(int argc, char **argv)
 {
 	size_t len, r, i;
-	int ch;
+	int ch, did;
 	FILE *f;
 	uint8_t buf[64];
 
@@ -67,11 +67,15 @@ main(int argc, char **argv)
 
         printf("const uint8_t %s[] = {\n", varname);
 
+	did = 0;
 	len = 0;
         for (;;) {
 		r = fread(buf, 1, sizeof(buf), f);
 		len += r;
 
+		if (r != 0)
+			did = 1;
+
 		printf("\t");
 		for (i = 0; i < r; ++i) {
 			printf("0x%x, ", buf[i]);
@@ -82,6 +86,17 @@ main(int argc, char **argv)
 			break;
 	}
 
+	if (!did) {
+		/*
+		 * if nothing was emitted, add a NUL byte.  This was
+		 * still produce an exact copy of the file because
+		 * `len' doesn't count this NUL byte.  It prevents the
+		 * "use of GNU empty initializer extension" warning
+		 * when bundling pages/about_empty.gmi
+		 */
+		printf("\t0x0\n");
+	}
+
 	printf("}; /* %s */\n", varname);
 
 	printf("size_t %s_len = %zu;\n", varname, len);