examples: diff: parse correct types for line-diffopts

examples/common.c

@@ -146,6 +146,25 @@ int match_uint16_arg(
 	return 1;
 }
 
+int match_uint32_arg(
+	uint32_t *out, struct args_info *args, const char *opt)
+{
+	const char *found = match_numeric_arg(args, opt);
+	uint16_t val;
+	char *endptr = NULL;
+
+	if (!found)
+		return 0;
+
+	val = (uint32_t)strtoul(found, &endptr, 0);
+	if (!endptr || *endptr != '\0')
+		fatal("expected number after argument", opt);
+
+	if (out)
+		*out = val;
+	return 1;
+}
+
 static int match_int_internal(
 	int *out, const char *str, int allow_negative, const char *opt)
 {

examples/common.h

@@ -73,6 +73,15 @@ extern int match_uint16_arg(
 	uint16_t *out, struct args_info *args, const char *opt);
 
 /**
+ * Check current `args` entry against `opt` string parsing as uint32.  If
+ * `opt` matches exactly, take the next arg as a uint16_t value; if `opt`
+ * is a prefix (equal sign optional), take the remainder of the arg as a
+ * uint32_t value; otherwise return 0.
+ */
+extern int match_uint32_arg(
+	uint32_t *out, struct args_info *args, const char *opt);
+
+/**
  * Check current `args` entry against `opt` string parsing as int.  If
  * `opt` matches exactly, take the next arg as an int value; if it matches
  * as a prefix (equal sign optional), take the remainder of the arg as a

examples/diff.c

@@ -293,11 +293,11 @@ static void parse_opts(struct opts *o, int argc, char *argv[])
 		else if (is_prefixed(a, "-B") || is_prefixed(a, "--break-rewrites"))
 			/* TODO: parse thresholds */
 			o->findopts.flags |= GIT_DIFF_FIND_REWRITES;
-		else if (!match_uint16_arg(
+		else if (!match_uint32_arg(
 				&o->diffopts.context_lines, &args, "-U") &&
-			!match_uint16_arg(
+			!match_uint32_arg(
 				&o->diffopts.context_lines, &args, "--unified") &&
-			!match_uint16_arg(
+			!match_uint32_arg(
 				&o->diffopts.interhunk_lines, &args, "--inter-hunk-context") &&
 			!match_uint16_arg(
 				&o->diffopts.id_abbrev, &args, "--abbrev") &&