vtls: Use bool for Curl_ssl_getsessionid() return type

The return type of this function is a boolean value, and even uses a
bool internally, so use bool in the function declaration as well as
the variables that store the return value, to avoid any confusion.

lib/vtls/curl_schannel.c

@@ -509,7 +509,7 @@ schannel_connect_step3(struct connectdata *conn, int sockindex)
   struct SessionHandle *data = conn->data;
   struct ssl_connect_data *connssl = &conn->ssl[sockindex];
   struct curl_schannel_cred *old_cred = NULL;
-  int incache;
+  bool incache;
 
   DEBUGASSERT(ssl_connect_3 == connssl->connecting_state);
 
@@ -550,6 +550,7 @@ schannel_connect_step3(struct connectdata *conn, int sockindex)
       incache = FALSE;
     }
   }
+
   if(!incache) {
     result = Curl_ssl_addsessionid(conn, (void *)connssl->cred,
                                    sizeof(struct curl_schannel_cred));

lib/vtls/cyassl.c

@@ -332,7 +332,7 @@ cyassl_connect_step3(struct connectdata *conn,
   void *old_ssl_sessionid=NULL;
   struct SessionHandle *data = conn->data;
   struct ssl_connect_data *connssl = &conn->ssl[sockindex];
-  int incache;
+  bool incache;
   SSL_SESSION *our_ssl_sessionid;
 
   DEBUGASSERT(ssl_connect_3 == connssl->connecting_state);
@@ -347,6 +347,7 @@ cyassl_connect_step3(struct connectdata *conn,
       incache = FALSE;
     }
   }
+
   if(!incache) {
     result = Curl_ssl_addsessionid(conn, our_ssl_sessionid,
                                    0 /* unknown size */);

lib/vtls/gtls.c

@@ -754,7 +754,7 @@ gtls_connect_step3(struct connectdata *conn,
   struct SessionHandle *data = conn->data;
   gnutls_session_t session = conn->ssl[sockindex].session;
   int rc;
-  int incache;
+  bool incache;
   void *ssl_sessionid;
 #ifdef HAS_ALPN
   gnutls_datum_t proto;

lib/vtls/openssl.c

@@ -2610,7 +2610,7 @@ static CURLcode ossl_connect_step3(struct connectdata *conn, int sockindex)
   void *old_ssl_sessionid = NULL;
   struct SessionHandle *data = conn->data;
   struct ssl_connect_data *connssl = &conn->ssl[sockindex];
-  int incache;
+  bool incache;
   SSL_SESSION *our_ssl_sessionid;
 
   DEBUGASSERT(ssl_connect_3 == connssl->connecting_state);
@@ -2646,7 +2646,7 @@ static CURLcode ossl_connect_step3(struct connectdata *conn, int sockindex)
 
   if(!incache) {
     result = Curl_ssl_addsessionid(conn, our_ssl_sessionid,
-                                    0 /* unknown size */);
+                                   0 /* unknown size */);
     if(result) {
       failf(data, "failed to store ssl session");
       return result;

lib/vtls/polarssl.c

@@ -488,7 +488,7 @@ polarssl_connect_step3(struct connectdata *conn,
   struct SessionHandle *data = conn->data;
   void *old_ssl_sessionid = NULL;
   ssl_session *our_ssl_sessionid = &conn->ssl[sockindex].ssn ;
-  int incache;
+  bool incache;
 
   DEBUGASSERT(ssl_connect_3 == connssl->connecting_state);
 
@@ -501,6 +501,7 @@ polarssl_connect_step3(struct connectdata *conn,
       incache = FALSE;
     }
   }
+
   if(!incache) {
     void *new_session = malloc(sizeof(ssl_session));
 

lib/vtls/vtls.c

@@ -316,9 +316,9 @@ Curl_ssl_connect_nonblocking(struct connectdata *conn, int sockindex,
  * Check if there's a session ID for the given connection in the cache, and if
  * there's one suitable, it is provided. Returns TRUE when no entry matched.
  */
-int Curl_ssl_getsessionid(struct connectdata *conn,
-                          void **ssl_sessionid,
-                          size_t *idsize) /* set 0 if unknown */
+bool Curl_ssl_getsessionid(struct connectdata *conn,
+                           void **ssl_sessionid,
+                           size_t *idsize) /* set 0 if unknown */
 {
   struct curl_ssl_session *check;
   struct SessionHandle *data = conn->data;

lib/vtls/vtls.h

@@ -23,14 +23,14 @@
  ***************************************************************************/
 #include "curl_setup.h"
 
-#include "openssl.h" /* OpenSSL versions */
-#include "gtls.h"   /* GnuTLS versions */
-#include "nssg.h"   /* NSS versions */
-#include "gskit.h"  /* Global Secure ToolKit versions */
-#include "polarssl.h" /* PolarSSL versions */
-#include "axtls.h"  /* axTLS versions */
-#include "cyassl.h"  /* CyaSSL versions */
-#include "curl_schannel.h" /* Schannel SSPI version */
+#include "openssl.h"        /* OpenSSL versions */
+#include "gtls.h"           /* GnuTLS versions */
+#include "nssg.h"           /* NSS versions */
+#include "gskit.h"          /* Global Secure ToolKit versions */
+#include "polarssl.h"       /* PolarSSL versions */
+#include "axtls.h"          /* axTLS versions */
+#include "cyassl.h"         /* CyaSSL versions */
+#include "curl_schannel.h"  /* Schannel SSPI version */
 #include "curl_darwinssl.h" /* SecureTransport (Darwin) version */
 
 #ifndef MAX_PINNED_PUBKEY_SIZE
@@ -92,9 +92,9 @@ CURLcode Curl_ssl_push_certinfo(struct SessionHandle * data, int certnum,
 /* Functions to be used by SSL library adaptation functions */
 
 /* extract a session ID */
-int Curl_ssl_getsessionid(struct connectdata *conn,
-                          void **ssl_sessionid,
-                          size_t *idsize) /* set 0 if unknown */;
+bool Curl_ssl_getsessionid(struct connectdata *conn,
+                           void **ssl_sessionid,
+                           size_t *idsize) /* set 0 if unknown */;
 /* add a new session ID */
 CURLcode Curl_ssl_addsessionid(struct connectdata *conn,
                                void *ssl_sessionid,