Avoid trying to free NULL ptrs. Comment on malloc usages.

 -Erik

1 files changed, 6 insertions, 4 deletions

diff --git a/shell/cmdedit.c b/shell/cmdedit.c
index 0f064b414..0de18e81f 100644
--- a/shell/cmdedit.c
+++ b/shell/cmdedit.c
@@ -370,14 +370,16 @@ void input_tab(char* command, char* prompt, int outputFd, int *cursor, int *len)
 
 void get_previous_history(struct history **hp, char* command)
 {
-        free((*hp)->s);
+        if ((*hp)->s)
+                free((*hp)->s);
         (*hp)->s = strdup(command);
         *hp = (*hp)->p;
 }
 
 void get_next_history(struct history **hp, char* command)
 {
-        free((*hp)->s);
+        if ((*hp)->s)
+                free((*hp)->s);
         (*hp)->s = strdup(command);
         *hp = (*hp)->n;
 }
@@ -654,7 +656,7 @@ extern void cmdedit_read_input(char* prompt, char command[BUFSIZ])
                 struct history *h = his_end;
 
                 if (!h) {
-                        /* No previous history */
+                        /* No previous history -- this memory is never freed */
                         h = his_front = malloc(sizeof(struct history));
                         h->n = malloc(sizeof(struct history));
 
@@ -666,7 +668,7 @@ extern void cmdedit_read_input(char* prompt, char command[BUFSIZ])
                         his_end = h->n;
                         history_counter++;
                 } else {
-                        /* Add a new history command */
+                        /* Add a new history command -- this memory is never freed */
                         h->n = malloc(sizeof(struct history));
 
                         h->n->p = h;