Subject: PR/69: Only consider arrays > 1 element when quickly figuring out if a (...)
Origin: FILE5_36-32-g479e0995 <https://github.com/file/file/commit/FILE5_36-32-g479e0995>
Upstream-Author: Christos Zoulas <christos@zoulas.com>
Date: Sat Mar 2 01:08:10 2019 +0000
Bug-Debian: https://bugs.debian.org/922874

    PR/69: Only consider arrays > 1 element when quickly figuring out if a
    file is JSON.

--- a/src/is_json.c
+++ b/src/is_json.c
@@ -52,7 +52,8 @@
 #define JSON_NUMBER	2
 #define JSON_OBJECT	3
 #define JSON_STRING	4
-#define JSON_MAX	5
+#define JSON_ARRAYN	5
+#define JSON_MAX	6
 
 /*
  * if JSON_COUNT != 0:
@@ -171,6 +172,7 @@
 	size_t *st, size_t lvl)
 {
 	const unsigned char *uc = *ucp;
+	int more = 0;	/* Array has more than 1 element */
 
 	DPRINTF("Parse array: ", uc, *ucp);
 	while (uc < ue) {
@@ -180,9 +182,12 @@
 			goto out;
 		switch (*uc) {
 		case ',':
+			more++;
 			uc++;
 			continue;
 		case ']':
+			if (more)
+				st[JSON_ARRAYN]++;
 			*ucp = uc + 1;
 			return 1;
 		default:
@@ -330,7 +335,7 @@
 		return 0;
 #if JSON_COUNT
 	/* bail quickly if not counting */
-	if (lvl > 1 && (st[JSON_OBJECT] || st[JSON_ARRAY]))
+	if (lvl > 1 && (st[JSON_OBJECT] || st[JSON_ARRAYN]))
 		return 1;
 #endif
 
@@ -373,7 +378,7 @@
 	*ucp = uc;
 	DPRINTF("End general: ", uc, *ucp);
 	if (lvl == 0)
-		return rv && (st[JSON_ARRAY] || st[JSON_OBJECT]);
+		return rv && (st[JSON_ARRAYN] || st[JSON_OBJECT]);
 	return rv;
 }
 
@@ -408,8 +413,10 @@
 #define P(n) st[n], st[n] > 1 ? "s" : ""
 	if (file_printf(ms, " (%" SIZE_T_FORMAT "u object%s, %" SIZE_T_FORMAT
 	    "u array%s, %" SIZE_T_FORMAT "u string%s, %" SIZE_T_FORMAT
-	    "u constant%s, %" SIZE_T_FORMAT "u number%s)", P(JSON_OBJECT),
-	    P(JSON_ARRAY), P(JSON_STRING), P(JSON_CONSTANT), P(JSON_NUMBER))
+	    "u constant%s, %" SIZE_T_FORMAT "u number%s, %" SIZE_T_FORMAT
+	    "u >1array%s)",
+	    P(JSON_OBJECT), P(JSON_ARRAY), P(JSON_STRING), P(JSON_CONSTANT),
+	    P(JSON_NUMBER), P(JSON_ARRAYN))
 	    == -1)
 		return -1;
 #endif