wallet: fix radio function memleaks

-total redesign of dogecoin_unregister_watch_address_with_node to alleviate calls to concat
-populate wallet->filename on dogecoin_wallet_new otherwise it's populated by name and freed
-added replace_last_after_delim which searchs for a match and replaces with replacement
-added remove_substr which returns a string with substr removed

include/dogecoin/utils.h

@@ -81,6 +81,7 @@ LIBDOGECOIN_API void prepend(char* s, const char* t);
 LIBDOGECOIN_API void append(char* s, char* t);
 LIBDOGECOIN_API char* concat(char* prefix, char* suffix);
 LIBDOGECOIN_API void slice(const char *str, char *result, size_t start, size_t end);
+LIBDOGECOIN_API void replace_last_after_delim(const char *str, char* delim, char* replacement);
 LIBDOGECOIN_API void text_to_hex(char* in, char* out);
 LIBDOGECOIN_API const char* get_build();
 LIBDOGECOIN_API char* getpass(const char *prompt);

include/dogecoin/wallet.h

@@ -71,7 +71,7 @@ DISABLE_WARNING_POP
 
 /** single key/value record */
 typedef struct dogecoin_wallet_ {
-    const char* filename;
+    const char filename[311]; // max path length
     FILE *dbfile;
     dogecoin_hdnode* masterkey;
     uint32_t next_childindex; //cached next child index

src/cli/spvnode.c

@@ -477,17 +477,22 @@ int main(int argc, char* argv[]) {
         printf("registered:     %d %s\n", res, address);
         uint64_t amount = dogecoin_get_balance(address);
         if (amount > 0) {
-            printf("amount:         %s\n", dogecoin_get_balance_str(address));
+            char* amount_str = dogecoin_get_balance_str(address);
+            printf("amount:         %s\n", amount_str);
             unsigned int utxo_count = dogecoin_get_utxos_length(address);
             if (utxo_count) {
                 printf("utxo count:     %d\n", utxo_count);
                 unsigned int i = 1;
                 for (; i <= utxo_count; i++) {
                     printf("txid:           %s\n", dogecoin_get_utxo_txid_str(address, i));
                     printf("vout:           %d\n", dogecoin_get_utxo_vout(address, i));
-                    printf("amount:         %s\n", dogecoin_get_utxo_amount(address, i));
+                    sleep(1);
+                    char* utxo_amount_str = dogecoin_get_utxo_amount(address, i);
+                    printf("amount:         %s\n", utxo_amount_str);
+                    dogecoin_free(utxo_amount_str);
                 }
             }
+            dogecoin_free(amount_str);
         }
         res = dogecoin_unregister_watch_address_with_node(address);
         printf("unregistered:   %s\n", res ? "true" : "false");

src/utils.c

@@ -620,6 +620,31 @@ void slice(const char *str, char *result, size_t start, size_t end)
     strncpy(result, str + start, end - start);
 }
 
+void remove_substr(char *string, char *sub) {
+    char *match;
+    int len = strlen(sub);
+    while ((match = strstr(string, sub))) {
+        *match = '\0';
+        strcat(string, match+len);
+    }
+}
+
+void replace_last_after_delim(const char *str, char* delim, char* replacement) {
+    char* tmp = strdup((char*)str);
+    char* new = tmp;
+    char *strptr = strtok(new, delim);
+    char* last = NULL;
+    while (strptr != NULL) {
+        last = strptr;
+        strptr = strtok(NULL, delim);
+    }
+    if (last) {
+        remove_substr(str, last);
+        append(str, replacement);
+    }
+    dogecoin_free(tmp);
+}
+
 /**
  * @brief function to convert ascii text to hexadecimal string
  *