Bug 1852662 - Fix UndefinedBehaviorSanitizer warning in mimebuf.cpp:132. r=BenC

Differential Revision: https://phabricator.services.mozilla.com/D222284

--HG--
extra : rebase_source : 4604bd88c3f31aa0b5443291acd65e55456fdc7e
extra : amend_source : 85b19c81ad1fd1c475e44c77c3df6d5e41e94186

mailnews/mime/src/mimebuf.cpp

@@ -19,6 +19,7 @@
 #include "prlog.h"
 #include "msgCore.h"
 #include "nsMimeStringResources.h"
+#include "mimeobj.h"
 
 extern "C" int mime_GrowBuffer(uint32_t desired_size, uint32_t element_size,
                                uint32_t quantum, char** buffer, int32_t* size) {
@@ -81,10 +82,12 @@ extern "C" int mime_ReBuffer(const char* net_buffer, int32_t net_buffer_size,
   return 0;
 }
 
-static int convert_and_send_buffer(
-    char* buf, int length, bool convert_newlines_p,
-    int32_t (*per_line_fn)(char* line, uint32_t line_length, void* closure),
-    void* closure) {
+static int convert_and_send_buffer(char* buf, int length,
+                                   bool convert_newlines_p,
+                                   int32_t (*per_line_fn)(const char* line,
+                                                          int32_t line_length,
+                                                          MimeObject* closure),
+                                   MimeObject* closure) {
   /* Convert the line terminator to the native form.
    */
   char* newline;
@@ -132,11 +135,13 @@ static int convert_and_send_buffer(
   return (*per_line_fn)(buf, length, closure);
 }
 
-extern "C" int mime_LineBuffer(
-    const char* net_buffer, int32_t net_buffer_size, char** bufferP,
-    int32_t* buffer_sizeP, uint32_t* buffer_fpP, bool convert_newlines_p,
-    int32_t (*per_line_fn)(char* line, uint32_t line_length, void* closure),
-    void* closure) {
+extern "C" int mime_LineBuffer(const char* net_buffer, int32_t net_buffer_size,
+                               char** bufferP, int32_t* buffer_sizeP,
+                               uint32_t* buffer_fpP, bool convert_newlines_p,
+                               int32_t (*per_line_fn)(const char* line,
+                                                      int32_t line_length,
+                                                      MimeObject* closure),
+                               MimeObject* closure) {
   int status = 0;
   if (*buffer_fpP > 0 && *bufferP && (*buffer_fpP < (uint32_t)*buffer_sizeP) &&
       (*bufferP)[*buffer_fpP - 1] == '\r' && net_buffer_size > 0 &&

mailnews/mime/src/mimebuf.h

@@ -20,11 +20,13 @@
 extern "C" int mime_GrowBuffer(uint32_t desired_size, uint32_t element_size,
                                uint32_t quantum, char** buffer, int32_t* size);
 
-extern "C" int mime_LineBuffer(
-    const char* net_buffer, int32_t net_buffer_size, char** bufferP,
-    int32_t* buffer_sizeP, int32_t* buffer_fpP, bool convert_newlines_p,
-    int32_t (*per_line_fn)(char* line, int32_t line_length, void* closure),
-    void* closure);
+extern "C" int mime_LineBuffer(const char* net_buffer, int32_t net_buffer_size,
+                               char** bufferP, int32_t* buffer_sizeP,
+                               int32_t* buffer_fpP, bool convert_newlines_p,
+                               int32_t (*per_line_fn)(const char* line,
+                                                      int32_t line_length,
+                                                      MimeObject* closure),
+                               MimeObject* closure);
 
 extern "C" int mime_ReBuffer(const char* net_buffer, int32_t net_buffer_size,
                              uint32_t desired_buffer_size, char** bufferP,

mailnews/mime/src/mimecryp.cpp

@@ -39,7 +39,7 @@ static int MimeEncrypted_parse_end(MimeObject*, bool);
 static int MimeEncrypted_add_child(MimeObject*, MimeObject*);
 
 static int MimeHandleDecryptedOutput(const char*, int32_t, void*);
-static int MimeHandleDecryptedOutputLine(char*, int32_t, MimeObject*);
+static int MimeHandleDecryptedOutputLine(const char*, int32_t, MimeObject*);
 static int MimeEncrypted_close_headers(MimeObject*);
 static int MimeEncrypted_emit_buffered_child(MimeObject*);
 
@@ -264,14 +264,11 @@ static int MimeHandleDecryptedOutput(const char* buf, int32_t buf_size,
 
   /* Is it truly safe to use ibuffer here?  I think so... */
   return mime_LineBuffer(buf, buf_size, &obj->ibuffer, &obj->ibuffer_size,
-                         &obj->ibuffer_fp, true,
-                         ((int (*)(char*, int32_t, void*))
-                          /* This cast is to turn void into MimeObject */
-                          MimeHandleDecryptedOutputLine),
+                         &obj->ibuffer_fp, true, MimeHandleDecryptedOutputLine,
                          obj);
 }
 
-static int MimeHandleDecryptedOutputLine(char* line, int32_t length,
+static int MimeHandleDecryptedOutputLine(const char* line, int32_t length,
                                          MimeObject* obj) {
   /* Largely the same as MimeMessage_parse_line (the other MIME container
    type which contains exactly one child.)

mailnews/mime/src/mimeobj.cpp

@@ -215,11 +215,7 @@ static int MimeObject_parse_buffer(const char* buffer, int32_t size,
   if (obj->closed_p) return -1;
 
   return mime_LineBuffer(buffer, size, &obj->ibuffer, &obj->ibuffer_size,
-                         &obj->ibuffer_fp, true,
-                         ((int (*)(char*, int32_t, void*))
-                          /* This cast is to turn void into MimeObject */
-                          obj->clazz->parse_line),
-                         obj);
+                         &obj->ibuffer_fp, true, obj->clazz->parse_line, obj);
 }
 
 static int MimeObject_parse_line(const char* line, int32_t length,

mailnews/mime/src/mimetext.cpp

@@ -35,9 +35,10 @@ static int MimeInlineText_parse_eof(MimeObject* obj, bool abort_p);
 static int MimeInlineText_parse_end(MimeObject*, bool);
 static int MimeInlineText_parse_decoded_buffer(const char*, int32_t,
                                                MimeObject*);
-static int MimeInlineText_rotate_convert_and_parse_line(char*, int32_t,
+static int MimeInlineText_rotate_convert_and_parse_line(const char*, int32_t,
                                                         MimeObject*);
-static int MimeInlineText_open_dam(char* line, int32_t length, MimeObject* obj);
+static int MimeInlineText_open_dam(const char* line, int32_t length,
+                                   MimeObject* obj);
 static int MimeInlineText_initializeCharset(MimeObject* obj);
 
 static int MimeInlineTextClassInitialize(MimeObjectClass* oclass) {
@@ -267,10 +268,7 @@ static int MimeInlineText_parse_decoded_buffer(const char* buf, int32_t size,
   // `parse_line` method instead of calling the `parse_line` method directly.
   return mime_LineBuffer(buf, size, &obj->ibuffer, &obj->ibuffer_size,
                          &obj->ibuffer_fp, true,
-                         ((int (*)(char*, int32_t, void*))
-                          /* This cast is to turn void into MimeObject */
-                          MimeInlineText_rotate_convert_and_parse_line),
-                         obj);
+                         MimeInlineText_rotate_convert_and_parse_line, obj);
 }
 
 #define MimeInlineText_grow_cbuffer(text, desired_size)                       \
@@ -279,7 +277,8 @@ static int MimeInlineText_parse_decoded_buffer(const char* buf, int32_t size,
                          &(text)->cbuffer_size)                               \
        : 0)
 
-static int MimeInlineText_convert_and_parse_line(char* line, int32_t length,
+static int MimeInlineText_convert_and_parse_line(const char* line,
+                                                 int32_t length,
                                                  MimeObject* obj) {
   int status;
   nsAutoCString converted;
@@ -309,7 +308,7 @@ static int MimeInlineText_convert_and_parse_line(char* line, int32_t length,
       line, length, text->charset, converted, obj->options->stream_closure);
 
   if (status == 0) {
-    line = (char*)converted.get();
+    line = converted.get();
     length = converted.Length();
   }
 
@@ -323,7 +322,7 @@ static int MimeInlineText_convert_and_parse_line(char* line, int32_t length,
 // In this function call, all buffered lines in lineDam will be sent to charset
 // detector and a charset will be used to parse all those line and following
 // lines in this mime obj.
-static int MimeInlineText_open_dam(char* line, int32_t length,
+static int MimeInlineText_open_dam(const char* line, int32_t length,
                                    MimeObject* obj) {
   MimeInlineText* text = (MimeInlineText*)obj;
   nsAutoCString detectedCharset;
@@ -375,20 +374,35 @@ static int MimeInlineText_open_dam(char* line, int32_t length,
   return status;
 }
 
-static int MimeInlineText_rotate_convert_and_parse_line(char* line,
-                                                        int32_t length,
-                                                        MimeObject* obj) {
+static int MimeInlineText_rotate_convert_and_parse_line(
+    const char* original_line, int32_t length, MimeObject* obj) {
   int status = 0;
   MimeInlineTextClass* textc = (MimeInlineTextClass*)obj->clazz;
 
   PR_ASSERT(!obj->closed_p);
   if (obj->closed_p) return -1;
 
+  const char* line = nullptr;
+  char* rotated_line = nullptr;
+
   // Rotate the line, if desired (this happens on the raw data, before any
   // charset conversion).
   if (obj->options && obj->options->rot13_p) {
-    status = textc->rot13_line(obj, line, length);
-    if (status < 0) return status;
+    rotated_line = (char*)PR_Malloc(length);
+    if (!rotated_line) {
+      return -1;
+    }
+    memcpy(rotated_line, line, length);
+
+    status = textc->rot13_line(obj, rotated_line, length);
+    if (status < 0) {
+      PR_Free(rotated_line);
+      return status;
+    }
+
+    line = rotated_line;
+  } else {
+    line = original_line;
   }
 
   // Now convert to the canonical charset, if desired.
@@ -435,5 +449,6 @@ static int MimeInlineText_rotate_convert_and_parse_line(char* line,
   } else
     status = obj->clazz->parse_line(line, length, obj);
 
+  PR_FREEIF(rotated_line);
   return status;
 }