Fix various potential OOM crashes.

There were several potential OOM crashes in __imlib_ListFilters(),
__imlib_ListLoaders() and __imlib_TrimLoaderList().

The fix of __imlib_TrimLoaderList() is from patch by
Yuriy M. Kaminskiy <yumkam@gmail.com>.

Author: kimwoelders

src/lib/Makefile.am

@@ -47,6 +47,7 @@ image.c \
 image.h \
 line.c \
 loaderpath.h \
+modules.c \
 polygon.c \
 rectangle.c \
 rend.c \

src/lib/dynamic_filters.c

@@ -15,11 +15,8 @@
 #include "dynamic_filters.h"
 #include "file.h"
 #include "image.h"
-#include "loaderpath.h"
 #include "script.h"
 
-static char       **__imlib_ListFilters(int *num_ret);
-
 static ImlibExternalFilter *filters = NULL;
 static int          dyn_initialised = 0;
 
@@ -101,7 +98,7 @@ __imlib_dynamic_filters_init()
 #ifdef FDEBUG
         printf("DEBUG: Loading Filters\n");
 #endif
-        list = __imlib_ListFilters(&num_filters);
+        list = __imlib_ListModules("filters", &num_filters);
         for (i = num_filters - 1; i >= 0; i--)
           {
              tptr = NULL;
@@ -150,40 +147,3 @@ __imlib_get_dynamic_filter(char *name)
      }
    return NULL;
 }
-
-/* loader dir */
-static char       **
-__imlib_ListFilters(int *num_ret)
-{
-   char              **list = NULL, **l, *s;
-   int                 num, i, pi = 0;
-
-   *num_ret = 0;
-   /* same for system loader path */
-   s = (char *)malloc(sizeof(SYS_LOADERS_PATH) + 8 + 1);
-   sprintf(s, SYS_LOADERS_PATH "/filters");
-   l = __imlib_FileDir(s, &num);
-   if (num > 0)
-     {
-        *num_ret += num;
-        list = realloc(list, sizeof(char *) * *num_ret);
-        for (i = 0; i < num; i++)
-          {
-             s = (char *)realloc(s,
-                                 sizeof(SYS_LOADERS_PATH) + 9 + strlen(l[i]) +
-                                 1);
-             sprintf(s, SYS_LOADERS_PATH "/filters/%s", l[i]);
-             list[pi + i] = strdup(s);
-          }
-        __imlib_FileFreeDirList(l, num);
-     }
-   free(s);
-
-   /* List currently contains *everything in there* we need to weed out
-    * the .so, .la, .a versions of the same loader or whatever else.
-    * dlopen can take an extension-less name and do the Right Thing
-    * with it, so that's what we'll give it. */
-   list = __imlib_TrimLoaderList(list, num_ret);
-
-   return list;
-}

src/lib/file.h

@@ -20,4 +20,6 @@ int                 __imlib_IsRealFile(const char *s);
 
 int                 __imlib_ItemInList(char **list, int size, char *item);
 
+char              **__imlib_ListModules(const char *what, int *num_ret);
+
 #endif

src/lib/image.c

@@ -594,88 +594,6 @@ __imlib_ProduceLoader(char *file)
    return l;
 }
 
-/* list all the filenames of loaders  in the system loaders dir and the user */
-/* loader dir */
-static char       **
-__imlib_ListLoaders(int *num_ret)
-{
-   char              **list = NULL, **l, *s;
-   int                 num, i, pi = 0;
-
-   *num_ret = 0;
-   /* same for system loader path */
-   s = (char *)malloc(sizeof(SYS_LOADERS_PATH) + 8 + 1);
-   sprintf(s, SYS_LOADERS_PATH "/loaders");
-   l = __imlib_FileDir(s, &num);
-   if (num > 0)
-     {
-        *num_ret += num;
-        list = realloc(list, sizeof(char *) * *num_ret);
-
-        for (i = 0; i < num; i++)
-          {
-             s = (char *)realloc(s,
-                                 sizeof(SYS_LOADERS_PATH) + 9 + strlen(l[i]) +
-                                 1);
-             sprintf(s, SYS_LOADERS_PATH "/loaders/%s", l[i]);
-             list[pi + i] = strdup(s);
-          }
-        __imlib_FileFreeDirList(l, num);
-     }
-   free(s);
-
-   /* List currently contains *everything in there* we need to weed out
-    * the .so, .la, .a versions of the same loader or whatever else.
-    * dlopen can take an extension-less name and do the Right Thing
-    * with it, so that's what we'll give it. */
-   list = __imlib_TrimLoaderList(list, num_ret);
-
-   return list;
-}
-
-char              **
-__imlib_TrimLoaderList(char **list, int *num)
-{
-   int                 i, n, size = 0;
-
-   char              **ret = NULL;
-
-   if (!list)
-      return NULL;
-   if (*num == 0)
-      return list;
-
-   n = *num;
-
-   for (i = 0; i < n; i++)
-     {
-        char               *ext;
-
-        if (!list[i])
-           continue;
-        ext = strrchr(list[i], '.');
-        if ((ext) && (
-#ifdef __CYGWIN__
-                        (!strcasecmp(ext, ".dll")) ||
-#endif
-                        (!strcasecmp(ext, ".so"))))
-          {
-             /* Don't add the same loader multiple times... */
-             if (!__imlib_ItemInList(ret, size, list[i]))
-               {
-                  ret = realloc(ret, sizeof(char *) * (size + 1));
-
-                  ret[size++] = strdup(list[i]);
-               }
-          }
-        if (list[i])
-           free(list[i]);
-     }
-   free(list);
-   *num = size;
-   return ret;
-}
-
 /* fre the struct for a loader and close its dlopen'd handle */
 static void
 __imlib_ConsumeLoader(ImlibLoader * l)
@@ -753,7 +671,7 @@ __imlib_LoadAllLoaders(void)
    char              **list;
 
    /* list all the loaders imlib can find */
-   list = __imlib_ListLoaders(&num);
+   list = __imlib_ListModules("loaders", &num);
    /* no loaders? well don't load anything */
    if (!list)
       return;

src/lib/image.h

@@ -135,7 +135,6 @@ void                __imlib_AddImagePixmapToCache(ImlibImagePixmap * ip);
 void                __imlib_RemoveImagePixmapFromCache(ImlibImagePixmap * ip);
 void                __imlib_CleanupImagePixmapCache(void);
 #endif
-char              **__imlib_TrimLoaderList(char **list, int *num);
 void                __imlib_RemoveAllLoaders(void);
 ImlibLoader        *__imlib_FindBestLoaderForFile(const char *file,
                                                   int for_save);

src/lib/modules.c

@@ -0,0 +1,88 @@
+#include "config.h"
+
+#include <stdlib.h>
+
+#include "file.h"
+#include "image.h"
+#include "loaderpath.h"
+
+static char       **
+__imlib_TrimLoaderList(char **list, int *num)
+{
+   int                 i, n, size = 0;
+
+   if (!list)
+      return NULL;
+
+   n = *num;
+
+   for (i = 0; i < n; i++)
+     {
+        char               *ext;
+
+        if (!list[i])
+           continue;
+        ext = strrchr(list[i], '.');
+        if ((ext) && (
+#ifdef __CYGWIN__
+                        (!strcasecmp(ext, ".dll")) ||
+#endif
+                        (!strcasecmp(ext, ".so"))))
+          {
+             /* Don't add the same loader multiple times... */
+             if (!__imlib_ItemInList(list, size, list[i]))
+               {
+                  list[size++] = list[i];
+                  continue;
+               }
+          }
+        free(list[i]);
+     }
+   if (!size)
+     {
+        free(list);
+        list = NULL;
+     }
+   else
+     {
+        list = realloc(list, size * sizeof(char *));
+     }
+   *num = size;
+   return list;
+}
+
+char              **
+__imlib_ListModules(const char *what, int *num_ret)
+{
+   char              **list = NULL, **l;
+   char                path[1024];
+   int                 num, i;
+
+   *num_ret = 0;
+
+   snprintf(path, sizeof(path), "%s/%s", SYS_LOADERS_PATH, what);
+   l = __imlib_FileDir(path, &num);
+   if (num <= 0)
+      return NULL;
+
+   list = malloc(num * sizeof(char *));
+   if (list)
+     {
+        for (i = 0; i < num; i++)
+          {
+             snprintf(path, sizeof(path), "%s/%s/%s",
+                      SYS_LOADERS_PATH, what, l[i]);
+             list[i] = strdup(path);
+          }
+        *num_ret = num;
+     }
+   __imlib_FileFreeDirList(l, num);
+
+   /* List currently contains *everything in there* we need to weed out
+    * the .so, .la, .a versions of the same loader or whatever else.
+    * dlopen can take an extension-less name and do the Right Thing
+    * with it, so that's what we'll give it. */
+   list = __imlib_TrimLoaderList(list, num_ret);
+
+   return list;
+}