fix undefined behaviour with string literals

src/execute.c

@@ -79,37 +79,39 @@ static struct cmd_func chat_commands[] = {
 
 /* Parses input command and puts args into arg array.
    Returns number of arguments on success, -1 on failure. */
-static int parse_command(WINDOW *w, ToxWindow *self, char *cmd, char (*args)[MAX_STR_SIZE])
+static int parse_command(WINDOW *w, ToxWindow *self, const char *input, char (*args)[MAX_STR_SIZE])
 {
+    char *cmd = strdup(input);
     int num_args = 0;
-    bool cmd_end = false;    /* flags when we get to the end of cmd */
-    char *end;               /* points to the end of the current arg */
+    int i = 0;    /* index of last char in an argument */
 
     /* characters wrapped in double quotes count as one arg */
-    while (!cmd_end && num_args < MAX_NUM_ARGS) {
-        if (*cmd == '\"') {
-            end = strchr(cmd + 1, '\"');
+    while (cmd[i] && num_args < MAX_NUM_ARGS) {
+        int qt_ofst = 0;    /* set to 1 to offset index for quote char at end of arg */
 
-            if (end++ == NULL) {    /* Increment past the end quote */
+        if (*cmd == '\"') {
+            qt_ofst = 1;
+
+            i = char_find(1, cmd, '\"');
+
+            if (cmd[i] == '\0') {
                 char *errmsg = "Invalid argument. Did you forget a closing \"?";
                 line_info_add(self, NULL, NULL, NULL, errmsg, SYS_MSG, 0, 0);
+                free(cmd);
                 return -1;
             }
-
-            cmd_end = *end == '\0';
         } else {
-            end = strchr(cmd, ' ');
-            cmd_end = end == NULL;
+            i = char_find(0, cmd, ' ');
         }
 
-        if (!cmd_end)
-            *end++ = '\0';    /* mark end of current argument */
+        memcpy(args[num_args], cmd, i + qt_ofst);
+        args[num_args++][i + qt_ofst] = '\0';
 
-        /* Copy from start of current arg to where we just inserted the null byte */
-        strcpy(args[num_args++], cmd);
-        cmd = end;
+        if (cmd[i] != '\0')
+            strcpy(cmd, &cmd[i + 1]);
     }
 
+    free(cmd);
     return num_args;
 }
 
@@ -129,13 +131,13 @@ static int do_command(WINDOW *w, ToxWindow *self, Tox *m, int num_args, int num_
     return 1;
 }
 
-void execute(WINDOW *w, ToxWindow *self, Tox *m, char *cmd, int mode)
+void execute(WINDOW *w, ToxWindow *self, Tox *m, const char *input, int mode)
 {
-    if (string_is_empty(cmd))
+    if (string_is_empty(input))
         return;
 
     char args[MAX_NUM_ARGS][MAX_STR_SIZE];
-    int num_args = parse_command(w, self, cmd, args);
+    int num_args = parse_command(w, self, input, args);
 
     if (num_args == -1)
         return;

src/execute.h

@@ -42,6 +42,6 @@ enum {
     GROUPCHAT_COMMAND_MODE,
 };
 
-void execute(WINDOW *w, ToxWindow *self, Tox *m, char *cmd, int mode);
+void execute(WINDOW *w, ToxWindow *self, Tox *m, const char *input, int mode);
 
 #endif /* #define _execute_h */

src/input.c

@@ -185,7 +185,8 @@ static void input_history(ToxWindow *self, wint_t key, int mx_x)
     ChatContext *ctx = self->chatwin;
 
     fetch_hist_item(ctx, key);
-    ctx->start = mx_x * (ctx->len / mx_x);
+    int wlen = wcswidth(ctx->line, sizeof(ctx->line));
+    ctx->start = wlen < mx_x ? 0 : wlen - mx_x + 1;
 }
 
 /* Handles non-printable input keys that behave the same for all types of chat windows.

src/misc_tools.c

@@ -108,7 +108,7 @@ char *hex_string_to_bin(const char *hex_string)
 }
 
 /* Returns 1 if the string is empty, 0 otherwise */
-int string_is_empty(char *string)
+int string_is_empty(const char *string)
 {
     return string[0] == '\0';
 }
@@ -197,23 +197,23 @@ int valid_nick(char *nick)
 void get_file_name(char *namebuf, int bufsize, const char *pathname)
 {
     int idx = strlen(pathname) - 1;
-
-    char tmpname[MAX_STR_SIZE];
-    snprintf(tmpname, sizeof(tmpname), "%s", pathname);
+    char *path = strdup(pathname);
 
     while (idx >= 0 && pathname[idx] == '/')
-        tmpname[idx--] = '\0';
+        path[idx--] = '\0';
 
-    char *filename = strrchr(tmpname, '/');
+    char *finalname = strdup(path);
+    const char *basenm = strrchr(path, '/');
 
-    if (filename != NULL) {
-        if (!strlen(++filename))
-            filename = tmpname;
-    } else {
-        filename = tmpname;
+    if (basenm != NULL) {
+        if (basenm[1])
+            strcpy(finalname, &basenm[1]);
     }
 
-    snprintf(namebuf, bufsize, "%s", filename);
+    snprintf(namebuf, bufsize, "%s", finalname);
+
+    free(finalname);
+    free(path);
 }
 
 /* converts str to all lowercase */
@@ -234,3 +234,17 @@ int get_nick_truncate(Tox *m, char *buf, int friendnum)
     buf[len] = '\0';
     return len;
 }
+
+/* returns index of the first instance of ch in s starting at idx.
+   returns length of s if char not found */
+int char_find(int idx, const char *s, char ch)
+{
+    int i = 0;
+
+    for (i = idx; s[i]; ++i) {
+        if (s[i] == ch)
+            break;
+    }
+
+    return i;
+}

src/misc_tools.h

@@ -52,7 +52,7 @@ struct tm *get_time(void);
 void update_unix_time(void);
 
 /* Returns 1 if the string is empty, 0 otherwise */
-int string_is_empty(char *string);
+int string_is_empty(const char *string);
 
 /* convert a multibyte string to a wide character string (must provide buffer) */
 int char_to_wcs_buf(wchar_t *buf, const char *string, size_t n);
@@ -89,4 +89,8 @@ void str_to_lower(char *str);
    Returns nick len on success, -1 on failure */
 int get_nick_truncate(Tox *m, char *buf, int friendnum);
 
+/* returns index of the first instance of ch in s starting at idx.
+   returns length of s if char not found */
+int char_find(int idx, const char *s, char ch);
+
 #endif /* #define _misc_tools_h */

src/toxic.c

@@ -641,7 +641,7 @@ int main(int argc, char *argv[])
     sort_friendlist_index();
     prompt_init_statusbar(prompt, m);
 
-    uint64_t last_save = get_unix_time();
+    uint64_t last_save = (uint64_t) time(NULL);
 
     while (true) {
         update_unix_time();