Merge branch 'infer-sa-fixes'HEADmaster

Fix several potential issues discovered by Infer.

Thanks to ZhipengXue97.

9 files changed, 65 insertions, 32 deletions

diff --git a/src/cmd_handlers.c b/src/cmd_handlers.c
index 79df65ef0..ea32df303 100644
--- a/src/cmd_handlers.c
+++ b/src/cmd_handlers.c
@@ -3701,6 +3701,11 @@ mark_cmd(const cmd_info_t *cmd_info)
 	}
 
 	expanded_path = expand_tilde(cmd_info->argv[1]);
+	if(expanded_path == NULL)
+	{
+		return CMDS_ERR_NO_MEM;
+	}
+
 	if(!is_path_absolute(expanded_path))
 	{
 		free(expanded_path);
diff --git a/src/lua/common.c b/src/lua/common.c
index 51d169d6c..553aaea75 100644
--- a/src/lua/common.c
+++ b/src/lua/common.c
@@ -76,13 +76,25 @@ vlua_cmn_check_opt_field(lua_State *lua, int table_idx, const char name[],
 
 	if(type != lua_type)
 	{
-		return luaL_error(lua, "`%s` value must be a %s",name,
+		return luaL_error(lua, "`%s` value must be a %s", name,
 				lua_typename(lua, lua_type));
 	}
 	return 1;
 }
 
 void *
+vlua_cmn_check_this(lua_State *lua, int idx)
+{
+	void *udata = lua_touserdata(lua, idx);
+	if(udata == NULL)
+	{
+		const char *type = lua_typename(lua, lua_type(lua, idx));
+		luaL_error(lua, "Value at %d must be user data, got %s", idx, type);
+	}
+	return udata;
+}
+
+void *
 vlua_cmn_to_pointer(lua_State *lua)
 {
 	void *ptr = (void *)lua_topointer(lua, -1);
diff --git a/src/lua/common.h b/src/lua/common.h
index bfd7e9f5a..acd6a2219 100644
--- a/src/lua/common.h
+++ b/src/lua/common.h
@@ -39,6 +39,11 @@ void vlua_cmn_check_field(struct lua_State *lua, int table_idx,
 int vlua_cmn_check_opt_field(struct lua_State *lua, int table_idx,
 		const char name[], int lua_type);
 
+/* Retrieves user data from a specified stack index aborting (Lua does
+ * longjmp()) if it's missing or isn't user data.  Returns user data pointer,
+ * never NULL. */
+void * vlua_cmn_check_this(struct lua_State *lua, int idx);
+
 /* Converts Lua value at the top of the stack into a C pointer without popping
  * it.  Returns the pointer. */
 void * vlua_cmn_to_pointer(struct lua_State *lua);
diff --git a/src/lua/vifmentry.c b/src/lua/vifmentry.c
index e50fe5bcb..1263c8e8f 100644
--- a/src/lua/vifmentry.c
+++ b/src/lua/vifmentry.c
@@ -137,7 +137,7 @@ VLUA_API(vifmentry_gc)(lua_State *lua)
 static int
 VLUA_API(vifmentry_gettarget)(lua_State *lua)
 {
-	vifm_entry_t *vifm_entry = lua_touserdata(lua, lua_upvalueindex(1));
+	vifm_entry_t *vifm_entry = vlua_cmn_check_this(lua, lua_upvalueindex(1));
 
 	if(vifm_entry->type != FT_LINK)
 	{
@@ -158,7 +158,7 @@ VLUA_API(vifmentry_gettarget)(lua_State *lua)
 static int
 VLUA_API(vifmentry_mimetype)(lua_State *lua)
 {
-	vifm_entry_t *vifm_entry = lua_touserdata(lua, lua_upvalueindex(1));
+	vifm_entry_t *vifm_entry = vlua_cmn_check_this(lua, lua_upvalueindex(1));
 
 	const char *mimetype = get_mimetype(vifm_entry->full_path,
 			/*resolve_symlinks=*/1);
diff --git a/src/lua/vifmjob.c b/src/lua/vifmjob.c
index aa3b7dedf..47a465e97 100644
--- a/src/lua/vifmjob.c
+++ b/src/lua/vifmjob.c
@@ -81,7 +81,12 @@ static const luaL_Reg vifmjob_methods[] = {
 	{ NULL,       NULL                       }
 };
 
-/* Address of this variable serves as a key in Lua table. */
+/*
+ * Address of this variable serves as a key in Lua table which maps VifmJob
+ * instances onto dictionary with such fields:
+ *  - "obj" - vifm_job_t user data
+ *  - "on_exit" - Lua callback to invoke when the job is done
+ */
 static char jobs_key;
 
 void
@@ -104,6 +109,7 @@ vifmjob_finish(lua_State *lua)
 		lua_pop(lua, 1);
 
 		bg_job_t *job = lua_touserdata(lua, -1);
+		assert(job != NULL && "List of Lua jobs includes a bad key!");
 		bg_job_set_exit_cb(job, NULL, NULL);
 	}
 
@@ -210,6 +216,7 @@ job_exit_cb(struct bg_job_t *job, void *arg)
 
 	lua_getfield(vlua->lua, -2, "obj");
 	vifm_job_t *vifm_job = lua_touserdata(vlua->lua, -1);
+	assert(vifm_job != NULL && "List of Lua jobs is includes bad element!");
 
 	/* Remove the table entry we've just used. */
 	lua_pushlightuserdata(vlua->lua, job);
diff --git a/src/lua/vifmview.c b/src/lua/vifmview.c
index 4ee77bd9e..8a174ff18 100644
--- a/src/lua/vifmview.c
+++ b/src/lua/vifmview.c
@@ -198,14 +198,14 @@ VLUA_API(cursor_index)(lua_State *lua)
 	const char *key = luaL_checkstring(lua, 2);
 	if(strcmp(key, "pos") == 0)
 	{
-		const unsigned int *id = lua_touserdata(lua, 1);
+		const unsigned int *id = vlua_cmn_check_this(lua, 1);
 		view_t *view = find_view(lua, *id);
 		lua_pushinteger(lua, view->list_pos + 1);
 		return 1;
 	}
 	else if(strcmp(key, "entry") == 0)
 	{
-		unsigned int *id = lua_touserdata(lua, 1);
+		unsigned int *id = vlua_cmn_check_this(lua, 1);
 		lua_pushlightuserdata(lua, id);
 		lua_pushcclosure(lua, VLUA_REF(cursor_entry), 1);
 		return 1;
@@ -225,7 +225,7 @@ VLUA_API(cursor_newindex)(lua_State *lua)
 		{
 			return 0;
 		}
-		const unsigned int *id = lua_touserdata(lua, 1);
+		const unsigned int *id = vlua_cmn_check_this(lua, 1);
 		view_t *view = find_view(lua, *id);
 		const int pos = luaL_checkinteger(lua, 3) - 1;
 		fpos_set_pos(view, pos);
@@ -253,7 +253,7 @@ VLUA_API(cursor_newindex)(lua_State *lua)
 static int
 VLUA_API(cursor_entry)(lua_State *lua)
 {
-	const unsigned int *id = lua_touserdata(lua, lua_upvalueindex(1));
+	const unsigned int *id = vlua_cmn_check_this(lua, lua_upvalueindex(1));
 	view_t *view = find_view(lua, *id);
 	vifmentry_new(lua, &view->dir_entry[view->list_pos]);
 	return 1;
@@ -340,7 +340,7 @@ VLUA_API(locopts_newindex)(lua_State *lua)
 static int
 do_opt(lua_State *lua, opt_t *opt, int set)
 {
-	const unsigned int *id = lua_touserdata(lua, 1);
+	const unsigned int *id = vlua_cmn_check_this(lua, 1);
 	view_t *view = find_view(lua, *id);
 
 	if(view == curr_view)
@@ -379,7 +379,7 @@ do_opt(lua_State *lua, opt_t *opt, int set)
 static int
 VLUA_IMPL(restore_curr_view)(lua_State *lua)
 {
-	view_t *curr = lua_touserdata(lua, lua_upvalueindex(1));
+	view_t *curr = vlua_cmn_check_this(lua, lua_upvalueindex(1));
 	curr_view = curr;
 	load_view_options(curr_view);
 	return 1;
@@ -389,7 +389,7 @@ VLUA_IMPL(restore_curr_view)(lua_State *lua)
 static int
 VLUA_IMPL(get_opt_wrapper)(lua_State *lua)
 {
-	opt_t *opt = lua_touserdata(lua, 1);
+	opt_t *opt = vlua_cmn_check_this(lua, 1);
 	return vlua_cmn_get_opt(lua, opt);
 }
 
@@ -397,7 +397,7 @@ VLUA_IMPL(get_opt_wrapper)(lua_State *lua)
 static int
 VLUA_IMPL(set_opt_wrapper)(lua_State *lua)
 {
-	opt_t *opt = lua_touserdata(lua, 1);
+	opt_t *opt = vlua_cmn_check_this(lua, 1);
 	return vlua_cmn_set_opt(lua, opt);
 }
 
diff --git a/src/lua/vlua_state.c b/src/lua/vlua_state.c
index 07015c860..1f44f5ba8 100644
--- a/src/lua/vlua_state.c
+++ b/src/lua/vlua_state.c
@@ -126,6 +126,8 @@ vlua_state_get(lua_State *lua)
 	lua_gettable(lua, LUA_REGISTRYINDEX);
 	vlua_t *vlua = lua_touserdata(lua, -1);
 	lua_pop(lua, 1);
+
+	assert(vlua != NULL && "Failed to obtain vlua state!");
 	return vlua;
 }
 
diff --git a/src/modes/cmdline.c b/src/modes/cmdline.c
index ca003a0d5..718222e75 100644
--- a/src/modes/cmdline.c
+++ b/src/modes/cmdline.c
@@ -2365,16 +2365,17 @@ static char *
 escape_cmd_for_pasting(const char str[])
 {
 	wchar_t *const wide_input = vifm_wcsdup(input_stat.line);
-	char *mb_input;
-	char *escaped;
+	if(wide_input == NULL)
+	{
+		return NULL;
+	}
 
 	wide_input[input_stat.index] = L'\0';
-	mb_input = to_multibyte(wide_input);
-
-	escaped = cmds_insertion_escape(mb_input, strlen(mb_input), str);
+	char *mb_input = to_multibyte(wide_input);
+	free(wide_input);
 
+	char *escaped = cmds_insertion_escape(mb_input, strlen(mb_input), str);
 	free(mb_input);
-	free(wide_input);
 
 	return escaped;
 }
diff --git a/src/utils/str.c b/src/utils/str.c
index 9f951ca75..d85e36df3 100644
--- a/src/utils/str.c
+++ b/src/utils/str.c
@@ -291,37 +291,38 @@ transform_ascii_str(const char str[], int (*f)(int), char buf[], size_t buf_len)
 }
 
 /* Transforms characters of the string to while they fit in the buffer by
- * calling specified function on them.  Returns zero on success or non-zero if
- * output buffer is too small. */
+ * calling specified function on them.  Returns zero on success or non-zero on
+ * error (output buffer is too small or out of memory) in which case buffer is
+ * filled with full UTF-8 characters from input. */
 static int
 transform_wide_str(const char str[], wint_t (*f)(wint_t), char buf[],
 		size_t buf_len)
 {
-	size_t copied;
-	int error;
-	wchar_t *wstring;
-	wchar_t *p;
-	char *narrow;
-
-	wstring = to_wide(str);
+	wchar_t *wstring = to_wide(str);
 	if(wstring == NULL)
 	{
 		(void)utf8_strcpy(buf, str, buf_len);
 		return 1;
 	}
 
-	p = wstring;
+	wchar_t *p = wstring;
 	while(*p != L'\0')
 	{
 		*p = f(*p);
 		++p;
 	}
 
-	narrow = to_multibyte(wstring);
-	copied = utf8_strcpy(buf, narrow, buf_len);
-	error = copied == 0U || narrow[copied - 1U] != '\0';
-
+	char *narrow = to_multibyte(wstring);
 	free(wstring);
+
+	if(narrow == NULL)
+	{
+		(void)utf8_strcpy(buf, str, buf_len);
+		return 1;
+	}
+
+	size_t copied = utf8_strcpy(buf, narrow, buf_len);
+	int error = (copied == 0U || narrow[copied - 1U] != '\0');
 	free(narrow);
 
 	return error;