Fix memory leak in SaveYourselfPhase2CB

Valgrind results before:

  definitely lost: 981 bytes in 37 blocks
  indirectly lost: 872 bytes in 6 blocks
    possibly lost: 0 bytes in 0 blocks
  still reachable: 991,316 bytes in 1,795 blocks
       suppressed: 0 bytes in 0 blocks

Valgrind results after:

  definitely lost: 800 bytes in 23 blocks
  indirectly lost: 872 bytes in 6 blocks
    possibly lost: 0 bytes in 0 blocks
  still reachable: 991,316 bytes in 1,795 blocks
       suppressed: 0 bytes in 0 blocks

Signed-off-by: Tim Wiederhake <twied@gmx.net>
Part-of: <https://gitlab.freedesktop.org/xorg/app/twm/-/merge_requests/29>

3 files changed, 65 insertions, 54 deletions

diff --git a/src/session.c b/src/session.c
index 92b25bb..af2b437 100644
--- a/src/session.c
+++ b/src/session.c
@@ -67,6 +67,7 @@ static XtInputId iceInputId;
 static char *twm_clientId;
 static TWMWinConfigEntry *winConfigHead = NULL;
 static Bool sent_save_done = 0;
+static SmProp *props[5];
 
 #define SAVEFILE_VERSION 2
 
@@ -676,8 +677,6 @@ SaveYourselfPhase2CB(SmcConn smcConn2, SmPointer clientData _X_UNUSED)
     const char *path;
     char *filename = NULL;
     Bool success = False;
-    SmProp prop1, prop2, prop3, *props[3];
-    SmPropValue prop1val, prop2val, prop3val;
     char discardCommand[80];
     int numVals, i;
     static int first_time = 1;
@@ -688,36 +687,38 @@ SaveYourselfPhase2CB(SmcConn smcConn2, SmPointer clientData _X_UNUSED)
 
     if (first_time) {
         char userId[20];
-        char hint = SmRestartIfRunning;
+        char *hint;
 
-        prop1.name = strdup(SmProgram);
-        prop1.type = strdup(SmARRAY8);
-        prop1.num_vals = 1;
-        prop1.vals = &prop1val;
-        prop1val.value = Argv[0];
-        prop1val.length = (int) strlen(Argv[0]);
+        props[0] = (SmProp *) calloc(1, sizeof(SmProp));
+        props[0]->name = strdup(SmProgram);
+        props[0]->type = strdup(SmARRAY8);
+        props[0]->num_vals = 1;
+        props[0]->vals = (SmPropValue *) calloc(1, sizeof(SmPropValue));
+        props[0]->vals[0].value = strdup(Argv[0]);
+        props[0]->vals[0].length = (int) strlen(Argv[0]);
 
         snprintf(userId, sizeof(userId), "%ld", (long) getuid());
-        prop2.name = strdup(SmUserID);
-        prop2.type = strdup(SmARRAY8);
-        prop2.num_vals = 1;
-        prop2.vals = &prop2val;
-        prop2val.value = (SmPointer) userId;
-        prop2val.length = (int) strlen(userId);
-
-        prop3.name = strdup(SmRestartStyleHint);
-        prop3.type = strdup(SmCARD8);
-        prop3.num_vals = 1;
-        prop3.vals = &prop3val;
-        prop3val.value = (SmPointer) & hint;
-        prop3val.length = 1;
-
-        props[0] = &prop1;
-        props[1] = &prop2;
-        props[2] = &prop3;
 
-        SmcSetProperties(smcConn2, 3, props);
+        props[1] = (SmProp *) calloc(1, sizeof(SmProp));
+        props[1]->name = strdup(SmUserID);
+        props[1]->type = strdup(SmARRAY8);
+        props[1]->num_vals = 1;
+        props[1]->vals = (SmPropValue *) calloc(1, sizeof(SmPropValue));
+        props[1]->vals[0].value = strdup(userId);
+        props[1]->vals[0].length = (int) strlen(userId);
+
+        hint = (char *) malloc(1);
+        hint[0] = SmRestartIfRunning;
+
+        props[2] = (SmProp *) calloc(1, sizeof(SmProp));
+        props[2]->name = strdup(SmRestartStyleHint);
+        props[2]->type = strdup(SmCARD8);
+        props[2]->num_vals = 1;
+        props[2]->vals = (SmPropValue *) calloc(1, sizeof(SmPropValue));
+        props[2]->vals[0].value = hint;
+        props[2]->vals[0].length = 1;
 
+        SmcSetProperties(smcConn2, 3, props);
         first_time = 0;
     }
 
@@ -770,13 +771,12 @@ SaveYourselfPhase2CB(SmcConn smcConn2, SmPointer clientData _X_UNUSED)
         }
     }
 
-    prop1.name = strdup(SmRestartCommand);
-    prop1.type = strdup(SmLISTofARRAY8);
-
-    prop1.vals = (SmPropValue *)
-        malloc((size_t) (Argc + 4) * sizeof(SmPropValue));
+    props[3] = (SmProp *) calloc(1, sizeof(SmProp));
+    props[3]->name = strdup(SmRestartCommand);
+    props[3]->type = strdup(SmLISTofARRAY8);
+    props[3]->vals = (SmPropValue *) calloc(Argc + 4, sizeof(SmPropValue));
 
-    if (!prop1.vals) {
+    if (!props[3]->vals) {
         success = False;
         goto bad;
     }
@@ -789,38 +789,36 @@ SaveYourselfPhase2CB(SmcConn smcConn2, SmPointer clientData _X_UNUSED)
             i++;
         }
         else {
-            prop1.vals[numVals].value = (SmPointer) Argv[i];
-            prop1.vals[numVals++].length = (int) strlen(Argv[i]);
+            props[3]->vals[numVals].value = (SmPointer) strdup(Argv[i]);
+            props[3]->vals[numVals++].length = (int) strlen(Argv[i]);
         }
     }
 
-    prop1.vals[numVals].value = strdup("-clientId");
-    prop1.vals[numVals++].length = 9;
+    props[3]->vals[numVals].value = strdup("-clientId");
+    props[3]->vals[numVals++].length = 9;
 
-    prop1.vals[numVals].value = strdup(twm_clientId);
-    prop1.vals[numVals++].length = (int) strlen(twm_clientId);
+    props[3]->vals[numVals].value = strdup(twm_clientId);
+    props[3]->vals[numVals++].length = (int) strlen(twm_clientId);
 
-    prop1.vals[numVals].value = strdup("-restore");
-    prop1.vals[numVals++].length = 8;
+    props[3]->vals[numVals].value = strdup("-restore");
+    props[3]->vals[numVals++].length = 8;
 
-    prop1.vals[numVals].value = strdup(filename);
-    prop1.vals[numVals++].length = (int) strlen(filename);
+    props[3]->vals[numVals].value = strdup(filename);
+    props[3]->vals[numVals++].length = (int) strlen(filename);
 
-    prop1.num_vals = numVals;
+    props[3]->num_vals = numVals;
 
     snprintf(discardCommand, sizeof(discardCommand), "rm %s", filename);
-    prop2.name = strdup(SmDiscardCommand);
-    prop2.type = strdup(SmARRAY8);
-    prop2.num_vals = 1;
-    prop2.vals = &prop2val;
-    prop2val.value = (SmPointer) discardCommand;
-    prop2val.length = (int) strlen(discardCommand);
 
-    props[0] = &prop1;
-    props[1] = &prop2;
+    props[4] = (SmProp *) calloc(1, sizeof(SmProp));
+    props[4]->name = strdup(SmDiscardCommand);
+    props[4]->type = strdup(SmARRAY8);
+    props[4]->num_vals = 1;
+    props[4]->vals = (SmPropValue *) calloc(1, sizeof(SmPropValue));
+    props[4]->vals[0].value = strdup(discardCommand);
+    props[4]->vals[0].length = (int) strlen(discardCommand);
 
-    SmcSetProperties(smcConn2, 2, props);
-    free(prop1.vals);
+    SmcSetProperties(smcConn2, 2, props + 3);
 
  bad:
     SmcSaveYourselfDone(smcConn2, success);
@@ -921,3 +919,13 @@ ConnectToSessionManager(char *previous_id, XtAppContext appContext)
                                (XtPointer) XtInputReadMask,
                                ProcessIceMsgProc, (XtPointer) iceConn);
 }
+
+void
+DestroySession(void)
+{
+    for (int i = 0; i < 5; ++i) {
+        if (props[i]) {
+            SmFreeProperty(props[i]);
+        }
+    }
+}
diff --git a/src/session.h b/src/session.h
index df91469..489ec0e 100644
--- a/src/session.h
+++ b/src/session.h
@@ -38,6 +38,7 @@ extern int GetWindowConfig(TwmWindow *theWindow, short *x, short *y,
                            Bool *width_ever_changed_by_user,
                            Bool *height_ever_changed_by_user);
 extern void ReadWinConfigFile(char *filename);
+extern void DestroySession(void);
 
 extern SmcConn smcConn;
 
diff --git a/src/twm.c b/src/twm.c
index 4be177c..1221bf8 100644
--- a/src/twm.c
+++ b/src/twm.c
@@ -905,6 +905,8 @@ Done(XtPointer client_data _X_UNUSED, XtSignalId *si2 _X_UNUSED)
         Reborder(CurrentTime);
         XCloseDisplay(dpy);
     }
+
+    DestroySession();
     exit(EXIT_SUCCESS);
 }