A memory leak occurs when command 'step' is followed by 'quit'

without having reached the final TSTOP.
New function DCtran_step_quit() removes the leak.

src/frontend/breakp.c

@@ -517,7 +517,7 @@ ft_bpcheck(struct plot *runplot, int iteration)
 
     if ((howmanysteps > 0) && (--howmanysteps == 0)) {
         if (steps > 1)
-            fprintf(cp_err, "Stopped after %d steps.\n", steps);
+            fprintf(cp_out, "Note: Stopped after %d steps.\n", steps);
         return (FALSE);
     }
 
@@ -694,3 +694,14 @@ printcond(struct dbcomm *d, FILE *fp)
         }
     }
 }
+
+
+/* just check if we are in 'step' mode */
+bool
+ft_stepcheck(void)
+{
+    if ((steps > 0) && (howmanysteps == 0)) {
+        return (TRUE);
+    }
+    return (FALSE);
+}

src/frontend/runcoms2.c

@@ -35,6 +35,7 @@ Author: 1985 Wayne A. Christopher, U. C. Berkeley CAD Group
 extern void line_free_x(struct card *deck, bool recurse);
 extern INPmodel *modtab;
 extern NGHASHPTR modtabhash;
+extern int DCtran_step_quit(CKTcircuit* ckt);
 
 #ifdef SHARED_MODULE
 extern void exec_controls(wordlist *newcontrols);
@@ -219,6 +220,10 @@ com_remcirc(wordlist *wl)
         EVTunsetup(ft_curckt->ci_ckt);
 #endif
 
+    /* remove remnants of run after incomplete transient sim with 'step' */
+    if (ft_curckt->ci_ckt)
+        DCtran_step_quit(ft_curckt->ci_ckt);
+
     if_cktfree(ft_curckt->ci_ckt, ft_curckt->ci_symtab);
     for (v = ft_curckt->ci_vars; v; v = next) {
         next = v->va_next;

src/include/ngspice/fteext.h

@@ -26,9 +26,10 @@ Modified: 1999 Paolo Nenzi - 2000 AlansFixes
 
 extern void ft_checkkids(void);
 
-/* breakpoint.c */
+/* breakp.c */
 
 extern bool ft_bpcheck(struct plot *runplot, int iteration);
+extern bool ft_stepcheck(void);
 extern void dbfree(struct dbcomm *db);
 extern void dbfree1(struct dbcomm *db);
 
@@ -173,29 +174,6 @@ extern struct dvec *ft_evaluate(struct pnode *node);
 /* ftesopt.c */
 extern struct variable *ft_getstat(struct circ *, char *);
 
-/* ginterface.c
-
-   extern bool gi_init();
-   extern bool gi_endpause;
-   extern bool gi_rottext;
-   extern int gi_fntheight;
-   extern int gi_fntwidth;
-   extern int gi_maxx;
-   extern int gi_maxy;
-   extern int gi_nolst;
-   extern int gi_nocolors;
-   extern int gi_package;
-   extern void gi_arc();
-   extern void gi_clearscreen();
-   extern void gi_close();
-   extern void gi_drawline();
-   extern void gi_redraw();
-   extern void gi_setcolor();
-   extern void gi_resetcolor();
-   extern void gi_setlinestyle();
-   extern void gi_text();
-   extern void gi_update();
-*/
 
 /* graf.c */
 
@@ -385,6 +363,5 @@ extern struct dvec* copycut(struct dvec* ov, struct dvec* newscalevec, int istar
 extern bool ft_intrpt;
 extern bool ft_setflag;
 
-/* error.c */
 
 #endif

src/spicelib/analysis/dctran.c

@@ -969,3 +969,22 @@ chkStep:
     }
     /* NOTREACHED */
 }
+
+
+/* If we have a 'step' command, and then 'quit' before reaching the final time,
+   remove the run plot memory. */
+int
+DCtran_step_quit(CKTcircuit* ckt) {
+    if (!ckt || !ckt->CKTcurJob) /* nothing to delete */
+        return 0;
+    if (ckt->CKTcurJob->JOBtype != 4) /* only tran sim */
+        return 0;
+    if (!ft_stepcheck()) /* only after 'step' */
+        return 0;
+    TRANan* job = (TRANan*)ckt->CKTcurJob;
+    if (!job->TRANplot) /* already done */
+        return 0;
+    SPfrontEnd->OUTendPlot(job->TRANplot);
+    job->TRANplot = NULL;
+    return(OK);
+}