Fix warnings found with clang analyzer

examples/sample.c

@@ -53,7 +53,7 @@ static int auth_callback(const char *prompt, char *buf, size_t len,
   if (echo) {
     while ((answer = fgets(buf, len, stdin)) == NULL);
     if ((ptr = strchr(buf, '\n'))) {
-      ptr = '\0';
+      *ptr = '\0';
     }
   } else {
     answer = getpass(prompt);

libssh/dh.c

@@ -882,7 +882,7 @@ static int match(const char *group, const char *object){
   const char *a;
   const char *z;
 
-  a = z = group;
+  z = group;
   do {
     a = strchr(z, ',');
     if (a == NULL) {

libssh/packet.c

@@ -126,7 +126,7 @@ int ssh_packet_socket_callback(const void *data, size_t receivedlen, void *user)
   char buffer[16] = {0};
   void *packet=NULL;
   int to_be_read;
-  int rc = SSH_ERROR;
+  int rc;
   uint32_t len;
   uint8_t padding;
   size_t processed=0; /* number of byte processed from the callback */
@@ -187,7 +187,6 @@ int ssh_packet_socket_callback(const void *data, size_t receivedlen, void *user)
         	/* give up, not enough data in buffer */
         	return processed;
         }
-        rc = SSH_ERROR;
 
         packet = (unsigned char *)data + processed;
 //        ssh_socket_read(session->socket,packet,to_be_read-current_macsize);

libssh/scp.c

@@ -112,6 +112,11 @@ int ssh_scp_init(ssh_scp scp){
   }
   if(scp->mode == SSH_SCP_WRITE){
 	  r=channel_read(scp->channel,&code,1,0);
+	  if(r<=0){
+	    ssh_set_error(scp->session,SSH_FATAL, "Error reading status code: %s",ssh_get_error(scp->session));
+	    scp->state=SSH_SCP_ERROR;
+	    return SSH_ERROR;
+	  }
 	  if(code != 0){
 		  ssh_set_error(scp->session,SSH_FATAL, "scp status code %ud not valid", code);
 		  scp->state=SSH_SCP_ERROR;
@@ -207,6 +212,11 @@ int ssh_scp_push_directory(ssh_scp scp, const char *dirname, int mode){
     return SSH_ERROR;
   }
   r=channel_read(scp->channel,&code,1,0);
+  if(r<=0){
+    ssh_set_error(scp->session,SSH_FATAL, "Error reading status code: %s",ssh_get_error(scp->session));
+    scp->state=SSH_SCP_ERROR;
+    return SSH_ERROR;
+  }
   if(code != 0){
     ssh_set_error(scp->session,SSH_FATAL, "scp status code %ud not valid", code);
     scp->state=SSH_SCP_ERROR;
@@ -239,6 +249,11 @@ int ssh_scp_push_directory(ssh_scp scp, const char *dirname, int mode){
     return SSH_ERROR;
   }
   r=channel_read(scp->channel,&code,1,0);
+  if(r<=0){
+    ssh_set_error(scp->session,SSH_FATAL, "Error reading status code: %s",ssh_get_error(scp->session));
+    scp->state=SSH_SCP_ERROR;
+    return SSH_ERROR;
+  }
   if(code != 0){
     ssh_set_error(scp->session,SSH_FATAL, "scp status code %ud not valid", code);
     scp->state=SSH_SCP_ERROR;
@@ -286,6 +301,11 @@ int ssh_scp_push_file(ssh_scp scp, const char *filename, size_t size, int mode){
     return SSH_ERROR;
   }
   r=channel_read(scp->channel,&code,1,0);
+  if(r<=0){
+    ssh_set_error(scp->session,SSH_FATAL, "Error reading status code: %s",ssh_get_error(scp->session));
+    scp->state=SSH_SCP_ERROR;
+    return SSH_ERROR;
+  }
   if(code != 0){
     ssh_set_error(scp->session,SSH_FATAL, "scp status code %ud not valid", code);
     scp->state=SSH_SCP_ERROR;

libssh/sftp.c

@@ -2400,9 +2400,9 @@ int sftp_rename(sftp_session sftp, const char *original, const char *newname) {
 /* Code written by Nick */
 /* Set file attributes on a file, directory or symbolic link. */
 int sftp_setstat(sftp_session sftp, const char *file, sftp_attributes attr) {
-  uint32_t id = sftp_get_new_id(sftp);
-  ssh_buffer buffer = buffer_new();
-  ssh_string path = string_from_char(file);
+  uint32_t id;
+  ssh_buffer buffer;
+  ssh_string path;
   sftp_message msg = NULL;
   sftp_status_message status = NULL;