Add comment to avoid mistake later, remove alloca

* Add comments so previous mistake is not repeated.
    * Remove alloca, replace it by strdup/asprintf.

Code now passes cppcheck.

source/run-dialog.c

@@ -114,6 +114,7 @@ static pid_t exec_cmd ( const char *cmd, int run_in_term )
             }
             retv         = reallocate ( retv, ( index + 2 ) * sizeof ( element* ) );
             retv[index]  = allocate ( sizeof ( element ) );
+            // remove trailing \n
             buffer[strlen ( buffer ) - 1] = '\0';
             char * start = NULL;
             retv[index]->index = strtol ( buffer, &start, 10 );
@@ -208,6 +209,7 @@ static void delete_entry ( const char *cmd )
             }
             retv               = reallocate ( retv, ( index + 2 ) * sizeof ( element* ) );
             retv[index]        = allocate ( sizeof ( element ) );
+            // remove trailing \n
             buffer[strlen ( buffer ) - 1] = '\0';
             retv[index]->index = strtol ( buffer, &start, 10 );
             snprintf ( retv[index]->name, RUN_DIALOG_NAME_LENGTH, "%s", start + 1 );
@@ -291,6 +293,7 @@ static char ** get_apps ( )
                 {
                     continue;
                 }
+                // remove trailing \n
                 buffer[strlen ( buffer ) - 1] = '\0';
                 char *start = NULL;
                 // Don't use result.

source/textbox.c

@@ -210,7 +210,7 @@ void textbox_draw ( textbox *tb )
     // clear canvas
     XftDrawRect ( draw, &tb->color_bg, 0, 0, tb->w, tb->h );
 
-    char *line = tb->text,
+    char *line = NULL,
     *text      = tb->text ? tb->text : "",
     *prompt    = tb->prompt ? tb->prompt : "";
 
@@ -229,8 +229,11 @@ void textbox_draw ( textbox *tb )
         length        = text_len + prompt_len;
         cursor_offset = MIN ( tb->cursor + prompt_len, length );
 
-        line = alloca ( length + 10 );
+        if(asprintf ( &line, "%s %s", prompt, text ) == -1) {
-        sprintf ( line, "%s %s", prompt, text );
+            // Something is _really_ wrong.. bail out
+            fprintf(stderr, "Failed to allocate string\n");
+            abort();
+        }
 
         // replace spaces so XftTextExtents8 includes their width
         for ( int i = 0; i < length; i++ )
@@ -248,6 +251,10 @@ void textbox_draw ( textbox *tb )
         // restore correct text string with spaces
         sprintf ( line, "%s %s", prompt, text );
     }
+    else
+    {
+        line = strdup(text);
+    }
 
     // calc full input text width
     // Calculate the right size, so no characters are cut off.
@@ -289,6 +296,8 @@ void textbox_draw ( textbox *tb )
         XftDrawRect ( draw, &tb->color_fg, cursor_x + SIDE_MARGIN, 2, cursor_width, line_height - 4 );
     }
 
+    free(line);
+
     XftDrawRect ( draw, &tb->color_bg, tb->w - SIDE_MARGIN, 0, SIDE_MARGIN, tb->h );
     // flip canvas to window
     XCopyArea ( display, canvas, tb->window, context, 0, 0, tb->w, tb->h, 0, 0 );