From 49f5527cd7bc74949910f8955f855bfe1b45788b Mon Sep 17 00:00:00 2001
From: Andrew Johnson <anj@anl.gov>
Date: Thu, 6 Dec 2018 16:35:30 -0600
Subject: [PATCH] iocsh: Add protection if realloc() fails

---
 src/libCom/iocsh/iocsh.cpp | 30 ++++++++++++++----------------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/src/libCom/iocsh/iocsh.cpp b/src/libCom/iocsh/iocsh.cpp
index ef646158e..03d4c28b4 100644
--- a/src/libCom/iocsh/iocsh.cpp
+++ b/src/libCom/iocsh/iocsh.cpp
@@ -599,12 +599,12 @@ iocshBody (const char *pathname, const char *commandLine, const char *macros)
     macPushScope(handle);
     macInstallMacros(handle, defines);
     
+    wasOkToBlock = epicsThreadIsOkToBlock();
+    epicsThreadSetOkToBlock(1);
+
     /*
      * Read commands till EOF or exit
      */
-    argc = 0;
-    wasOkToBlock = epicsThreadIsOkToBlock();
-    epicsThreadSetOkToBlock(1);
     for (;;) {
         /*
          * Read a line
@@ -676,15 +676,15 @@ iocshBody (const char *pathname, const char *commandLine, const char *macros)
         redirect = NULL;
         for (;;) {
             if (argc >= argvCapacity) {
-                char **av;
-                argvCapacity += 50;
-                av = (char **)realloc (argv, argvCapacity * sizeof *argv);
-                if (av == NULL) {
+                int newCapacity = argvCapacity + 20;
+                char **newv = (char **)realloc (argv, newCapacity * sizeof *argv);
+                if (newv == NULL) {
                     fprintf (epicsGetStderr(), "Out of memory!\n");
                     argc = -1;
                     break;
                 }
-                argv = av;
+                argv = newv;
+                argvCapacity = newCapacity;
             }
             c = line[icin++];
             if (c == '\0')
@@ -833,16 +833,14 @@ iocshBody (const char *pathname, const char *commandLine, const char *macros)
                         break;
                     }
                     if (iarg >= argBufCapacity) {
-                        void *np;
-
-                        argBufCapacity += 20;
-                        np = realloc (argBuf, argBufCapacity * sizeof *argBuf);
-                        if (np == NULL) {
+                        int newCapacity = argBufCapacity + 20;
+                        void *newBuf = realloc(argBuf, newCapacity * sizeof *argBuf);
+                        if (newBuf == NULL) {
                             fprintf (epicsGetStderr(), "Out of memory!\n");
-                            argBufCapacity -= 20;
                             break;
                         }
-                        argBuf = (iocshArgBuf *)np;
+                        argBuf = (iocshArgBuf *) newBuf;
+                        argBufCapacity = newCapacity;
                     }
                     if (piocshFuncDef->arg[iarg]->type == iocshArgArgv) {
                         argBuf[iarg].aval.ac = argc-iarg;
@@ -887,7 +885,7 @@ iocshBody (const char *pathname, const char *commandLine, const char *macros)
     errlogFlush();
     if (readlineContext)
         epicsReadlineEnd(readlineContext);
-    epicsThreadSetOkToBlock( wasOkToBlock);
+    epicsThreadSetOkToBlock(wasOkToBlock);
     return 0;
 }