[Core] switch_mprintf: Increase the size of loop variables in the printf() implementation. Add unit-tests disabled by default.

src/switch_mprintf.c

@@ -680,8 +680,8 @@ static int vxprintf(void (*func) (void *, const char *, int),	/* Consumer of tex
 		case etSQLESCAPE2:
 		case etSQLESCAPE4:
 		case etSQLESCAPE3:{
-				int i, j, n, ch, isnull;
-				int needQuote;
+				size_t i, j, n, ch;
+				int needQuote, isnull;
 				char *escarg = va_arg(ap, char *);
 				isnull = escarg == 0;
 				if (isnull)

tests/unit/switch_core.c

@@ -36,6 +36,8 @@
 #include <openssl/ssl.h>
 #endif
 
+#define ENABLE_SNPRINTFV_TESTS 0 /* Do not turn on for CI as this requires a lot of RAM */
+
 FST_CORE_BEGIN("./conf")
 {
 	FST_SUITE_BEGIN(switch_core)
@@ -51,6 +53,48 @@ FST_CORE_BEGIN("./conf")
 		}
 		FST_TEARDOWN_END()
 
+#if ENABLE_SNPRINTFV_TESTS
+		FST_TEST_BEGIN(test_snprintfv_1)
+		{
+			size_t src_buf_size = 0x100000001;
+			char* src = calloc(1, src_buf_size);
+
+			if (!src) {
+				printf("bad allocation\n");
+
+				return -1;
+			}
+
+			src[0] = '\xc0';
+			memset(src + 1, '\x80', 0xffffffff);
+
+			char dst[256];
+			switch_snprintfv(dst, 256, "'%!q'", src);
+			free(src);
+		}
+		FST_TEST_END()
+
+		FST_TEST_BEGIN(test_snprintfv_2)
+		{
+#define STR_LEN ((0x100000001 - 3) / 2)
+
+				char* src = calloc(1, STR_LEN + 1); /* Account for NULL byte. */
+
+				if (!src) { return -1; }
+
+				memset(src, 'a', STR_LEN);
+
+				char* dst = calloc(1, STR_LEN + 3); /* Account for extra quotes and NULL byte */
+				if (!dst) { return -1; }
+
+				switch_snprintfv(dst, 2 * STR_LEN + 3, "'%q'", src);
+
+				free(src);
+				free(dst);
+		}
+		FST_TEST_END()
+#endif
+
 		FST_TEST_BEGIN(test_switch_event_add_header_leak)
 		{
 			switch_event_t* event;