From: Wolfgang Stöggl <c72578@yahoo.de>
Date: Sat, 7 Sep 2019 20:27:22 +0000 (+0200)
Subject: Use temp pointer for realloc()
X-Git-Tag: v1.8.0~58
X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=7aeeb69bf663fd0089e3a9cd72694691a1cfb82f;p=thirdparty%2Frrdtool-1.x.git

Use temp pointer for realloc()

- Fixes the following Cppcheck 1.89 errors:
  [src/rrd_cgi.c:295] (error) Common realloc mistake:'varheap'
    nulled but not freed upon failure [memleakOnRealloc]
  [src/rrd_cgi.c:1138] (error) Common realloc mistake: 'argv'
    nulled but not freed upon failure [memleakOnRealloc]
  [src/rrd_graph.c:1211] (error) Common realloc mistake: 'steparray'
    nulled but not freed upon failure [memleakOnRealloc]
---

diff --git a/src/rrd_cgi.c b/src/rrd_cgi.c
index 35be69d6..8576a9bf 100644
--- a/src/rrd_cgi.c
+++ b/src/rrd_cgi.c
@@ -198,6 +198,7 @@ typedef struct {
    start with a heapsize of 10 variables */
 #define INIT_VARSTORE_SIZE	10
 static vardata *varheap = NULL;
+static vardata *varheap_tmp = NULL; /* temp variable for realloc() */
 static size_t varheap_size = 0;
 
 /* allocate and initialize variable heap */
@@ -292,11 +293,13 @@ static const char *putvar(
         /* ran out of heap: resize heap to double size */
         size_t    new_size = varheap_size * 2;
 
-        varheap = (vardata *) (realloc(varheap, sizeof(vardata) * new_size));
-        if (!varheap) {
+        varheap_tmp =
+            (vardata *) (realloc(varheap, sizeof(vardata) * new_size));
+        if (!varheap_tmp) {
             fprintf(stderr, "ERROR: Unable to realloc variable heap\n");
             return NULL;
         }
+        varheap = varheap_tmp;
         /* initialize newly allocated memory */ ;
         memset(&varheap[varheap_size], 0, sizeof(vardata) * varheap_size);
         varheap_size = new_size;
@@ -1030,6 +1033,7 @@ static char *scanargs(
     /* local array of arguments while parsing */
     int       argc = 1;
     char    **argv;
+    char    **argv_tmp; /* temp variable for realloc() */
 
 #ifdef DEBUG_PARSER
     printf("<-- scanargs(%s) -->\n", line);
@@ -1135,10 +1139,11 @@ static char *scanargs(
         if (argc == argsz - 2) {
             /* resize argument array */
             argsz *= 2;
-            argv = (char **) rrd_realloc(argv, argsz * sizeof(char *));
-            if (*argv == NULL) {
+            argv_tmp = (char **) rrd_realloc(argv, argsz * sizeof(char *));
+            if (*argv_tmp == NULL) {
                 return NULL;
             }
+            argv = argv_tmp;
         }
     }
 
diff --git a/src/rrd_graph.c b/src/rrd_graph.c
index f0e81314..64adcb27 100644
--- a/src/rrd_graph.c
+++ b/src/rrd_graph.c
@@ -1121,6 +1121,7 @@ int data_calc(
     int       gdi;
     int       dataidx;
     long     *steparray, rpi;
+    long     *steparray_tmp;    /* temp variable for realloc() */
     int       stepcnt;
     time_t    now;
     rpnstack_t rpnstack;
@@ -1208,7 +1209,7 @@ int data_calc(
 
                         /* add one entry to the array that keeps track of the step sizes of the
                          * data sources going into the CDEF. */
-                        if ((steparray =
+                        if ((steparray_tmp =
                              (long *) rrd_realloc(steparray,
                                                   (++stepcnt +
                                                    1) *
@@ -1218,6 +1219,7 @@ int data_calc(
                             rpnstack_free(&rpnstack);
                             return -1;
                         };
+                        steparray = steparray_tmp;
 
                         steparray[stepcnt - 1] = im->gdes[ptr].step;