From ad5988af46f5ca698115140f9252882286539f72 Mon Sep 17 00:00:00 2001
From: Oleg Oshmyan <chortos@inbox.lv>
Date: Fri, 30 Oct 2015 01:33:30 +0200
Subject: [PATCH] directwrite: improve error handling

  * Check malloc and calloc return values.
  * Abort if a name can't be fetched, rather than supply a NULL
    string to fontselect causing it to crash.
  * Make sure to free all allocated memory.
  * Always check FAILED(hr) before using the value of any output
    argument returned by DirectWrite, because it is not clear whether
    they are guaranteed to have correct values in case of error.
---
 libass/ass_directwrite.c | 74 +++++++++++++++++++++++++++-------------
 1 file changed, 51 insertions(+), 23 deletions(-)

diff --git a/libass/ass_directwrite.c b/libass/ass_directwrite.c
index e07b607..cb21dd4 100644
--- a/libass/ass_directwrite.c
+++ b/libass/ass_directwrite.c
@@ -520,22 +520,23 @@ static void add_font(IDWriteFont *font, IDWriteFontFamily *fontFamily,
     IDWriteLocalizedStrings *psNames;
     hr = IDWriteFont_GetInformationalStrings(font,
             DWRITE_INFORMATIONAL_STRING_POSTSCRIPT_NAME, &psNames, &exists);
-    if (FAILED(hr)) {
-        IDWriteFont_Release(font);
-        return;
-    }
+    if (FAILED(hr))
+        goto cleanup;
 
     if (exists) {
         hr = IDWriteLocalizedStrings_GetString(psNames, 0, temp_name, NAME_MAX_LENGTH);
         if (FAILED(hr)) {
             IDWriteLocalizedStrings_Release(psNames);
-            IDWriteFont_Release(font);
-            return;
+            goto cleanup;
         }
 
         temp_name[NAME_MAX_LENGTH-1] = 0;
         size_needed = WideCharToMultiByte(CP_UTF8, 0, temp_name, -1, NULL, 0, NULL, NULL);
         char *mbName = (char *) malloc(size_needed);
+        if (!mbName) {
+            IDWriteLocalizedStrings_Release(psNames);
+            goto cleanup;
+        }
         WideCharToMultiByte(CP_UTF8, 0, temp_name, -1, mbName, size_needed, NULL, NULL);
         meta.postscript_name = mbName;
 
@@ -545,25 +546,32 @@ static void add_font(IDWriteFont *font, IDWriteFontFamily *fontFamily,
     IDWriteLocalizedStrings *fontNames;
     hr = IDWriteFont_GetInformationalStrings(font,
             DWRITE_INFORMATIONAL_STRING_FULL_NAME, &fontNames, &exists);
-    if (FAILED(hr)) {
-        IDWriteFont_Release(font);
-        return;
-    }
+    if (FAILED(hr))
+        goto cleanup;
 
     if (exists) {
         meta.n_fullname = IDWriteLocalizedStrings_GetCount(fontNames);
         meta.fullnames = (char **) calloc(meta.n_fullname, sizeof(char *));
+        if (!meta.fullnames) {
+            IDWriteLocalizedStrings_Release(fontNames);
+            goto cleanup;
+        }
         for (int k = 0; k < meta.n_fullname; k++) {
             hr = IDWriteLocalizedStrings_GetString(fontNames, k,
                                                    temp_name,
                                                    NAME_MAX_LENGTH);
             if (FAILED(hr)) {
-                continue;
+                IDWriteLocalizedStrings_Release(fontNames);
+                goto cleanup;
             }
 
             temp_name[NAME_MAX_LENGTH-1] = 0;
             size_needed = WideCharToMultiByte(CP_UTF8, 0, temp_name, -1, NULL, 0, NULL, NULL);
             char *mbName = (char *) malloc(size_needed);
+            if (!mbName) {
+                IDWriteLocalizedStrings_Release(fontNames);
+                goto cleanup;
+            }
             WideCharToMultiByte(CP_UTF8, 0, temp_name, -1, mbName, size_needed, NULL, NULL);
             meta.fullnames[k] = mbName;
         }
@@ -573,26 +581,33 @@ static void add_font(IDWriteFont *font, IDWriteFontFamily *fontFamily,
     IDWriteLocalizedStrings *familyNames;
     hr = IDWriteFont_GetInformationalStrings(font,
             DWRITE_INFORMATIONAL_STRING_WIN32_FAMILY_NAMES, &familyNames, &exists);
-    if (!exists)
+    if (FAILED(hr) || !exists)
         hr = IDWriteFontFamily_GetFamilyNames(fontFamily, &familyNames);
-    if (FAILED(hr)) {
-        IDWriteFont_Release(font);
-        return;
-    }
+    if (FAILED(hr))
+        goto cleanup;
 
     meta.n_family = IDWriteLocalizedStrings_GetCount(familyNames);
     meta.families = (char **) calloc(meta.n_family, sizeof(char *));
+    if (!meta.families) {
+        IDWriteLocalizedStrings_Release(familyNames);
+        goto cleanup;
+    }
     for (int k = 0; k < meta.n_family; k++) {
         hr = IDWriteLocalizedStrings_GetString(familyNames, k,
                                                temp_name,
                                                NAME_MAX_LENGTH);
         if (FAILED(hr)) {
-            continue;
+            IDWriteLocalizedStrings_Release(familyNames);
+            goto cleanup;
         }
 
         temp_name[NAME_MAX_LENGTH-1] = 0;
         size_needed = WideCharToMultiByte(CP_UTF8, 0, temp_name, -1, NULL, 0, NULL, NULL);
         char *mbName = (char *) malloc(size_needed);
+        if (!mbName) {
+            IDWriteLocalizedStrings_Release(familyNames);
+            goto cleanup;
+        }
         WideCharToMultiByte(CP_UTF8, 0, temp_name, -1, mbName, size_needed, NULL, NULL);
         meta.families[k] = mbName;
     }
@@ -601,17 +616,30 @@ static void add_font(IDWriteFont *font, IDWriteFontFamily *fontFamily,
     meta.is_postscript = is_postscript(font);
 
     FontPrivate *font_priv = (FontPrivate *) calloc(1, sizeof(*font_priv));
+    if (!font_priv)
+        goto cleanup;
     font_priv->font = font;
+    font = NULL;
 
     ass_font_provider_add_font(provider, &meta, NULL, 0, font_priv);
 
-    for (int k = 0; k < meta.n_family; k++)
-        free(meta.families[k]);
-    for (int k = 0; k < meta.n_fullname; k++)
-        free(meta.fullnames[k]);
-    free(meta.fullnames);
-    free(meta.families);
+cleanup:
+    if (meta.families) {
+        for (int k = 0; k < meta.n_family; k++)
+            free(meta.families[k]);
+        free(meta.families);
+    }
+
+    if (meta.fullnames) {
+        for (int k = 0; k < meta.n_fullname; k++)
+            free(meta.fullnames[k]);
+        free(meta.fullnames);
+    }
+
     free(meta.postscript_name);
+
+    if (font)
+        IDWriteFont_Release(font);
 }
 
 /*
-- 
2.40.0