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authorRickard Green <[email protected]>2017-09-06 17:00:14 +0200
committerRickard Green <[email protected]>2017-10-11 16:59:40 +0200
commitbb0b43eae854125688f3143e53c8974cafed4ad2 (patch)
tree648c103b0777d951b0e4a44b6615753d2748a2ea /lib/stdlib/doc/src
parent02fd746c40e829adbe77cc526c7df904698e2534 (diff)
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Don't allow null chars in various strings
Various places that now reject null chars inside strings - Primitive file operations reject it in filenames. - Primitive environment variable operations reject it in names and values. - os:cmd() reject it in its input. Also '=' characters are rejected by primitive environment variable operations in environment variable names. Documentation has been updated to document null characters in these types of data as invalid. Currently these operations accept null chars at the end of strings, but that will change in the future.
Diffstat (limited to 'lib/stdlib/doc/src')
-rw-r--r--lib/stdlib/doc/src/filelib.xml24
-rw-r--r--lib/stdlib/doc/src/filename.xml30
-rw-r--r--lib/stdlib/doc/src/unicode_usage.xml8
3 files changed, 59 insertions, 3 deletions
diff --git a/lib/stdlib/doc/src/filelib.xml b/lib/stdlib/doc/src/filelib.xml
index 80c4acffdb..c531b10d50 100644
--- a/lib/stdlib/doc/src/filelib.xml
+++ b/lib/stdlib/doc/src/filelib.xml
@@ -45,6 +45,30 @@
<p>For more information about raw filenames, see the
<seealso marker="kernel:file"><c>file</c></seealso> module.</p>
+
+ <note>
+ <p>
+ Functionality in this module generally assumes valid input and
+ does not necessarily fail on input that does not use a valid
+ encoding, but may instead very likely produce invalid output.
+ </p>
+ <p>
+ File operations used to accept filenames containing
+ null characters (integer value zero). This caused
+ the name to be truncated and in some cases arguments
+ to primitive operations to be mixed up. Filenames
+ containing null characters inside the filename
+ are now <em>rejected</em> and will cause primitive
+ file operations to fail.
+ </p>
+ </note>
+ <warning><p>
+ Currently null characters at the end of the filename
+ will be accepted by primitive file operations. Such
+ filenames are however still documented as invalid. The
+ implementation will also change in the future and
+ reject such filenames.
+ </p></warning>
</description>
<datatypes>
diff --git a/lib/stdlib/doc/src/filename.xml b/lib/stdlib/doc/src/filename.xml
index 14fd5ef787..d2608ad542 100644
--- a/lib/stdlib/doc/src/filename.xml
+++ b/lib/stdlib/doc/src/filename.xml
@@ -46,7 +46,10 @@
filename by removing redundant directory separators, use
<seealso marker="#join/1"><c>join/1</c></seealso>.</p>
- <p>The module supports raw filenames in the way that if a binary is
+ <p>
+ The module supports
+ <seealso marker="unicode_usage#notes-about-raw-filenames">raw
+ filenames</seealso> in the way that if a binary is
present, or the filename cannot be interpreted according to the return
value of <seealso marker="kernel:file#native_name_encoding/0">
<c>file:native_name_encoding/0</c></seealso>, a raw filename is also
@@ -56,6 +59,30 @@
(the join operation is performed of course). For more information
about raw filenames, see the
<seealso marker="kernel:file"><c>file</c></seealso> module.</p>
+
+ <note>
+ <p>
+ Functionality in this module generally assumes valid input and
+ does not necessarily fail on input that does not use a valid
+ encoding, but may instead very likely produce invalid output.
+ </p>
+ <p>
+ File operations used to accept filenames containing
+ null characters (integer value zero). This caused
+ the name to be truncated and in some cases arguments
+ to primitive operations to be mixed up. Filenames
+ containing null characters inside the filename
+ are now <em>rejected</em> and will cause primitive
+ file operations to fail.
+ </p>
+ </note>
+ <warning><p>
+ Currently null characters at the end of the filename
+ will be accepted by primitive file operations. Such
+ filenames are however still documented as invalid. The
+ implementation will also change in the future and
+ reject such filenames.
+ </p></warning>
</description>
<datatypes>
<datatype>
@@ -555,6 +582,7 @@ unsafe</pre>
["a:/","msdev","include"]</pre>
</desc>
</func>
+
</funcs>
</erlref>
diff --git a/lib/stdlib/doc/src/unicode_usage.xml b/lib/stdlib/doc/src/unicode_usage.xml
index 26dc46719e..789e063c12 100644
--- a/lib/stdlib/doc/src/unicode_usage.xml
+++ b/lib/stdlib/doc/src/unicode_usage.xml
@@ -719,8 +719,8 @@ Eshell V5.10.1 (abort with ^G)
</section>
<section>
- <title>Unicode Filenames</title>
<marker id="unicode_file_names"/>
+ <title>Unicode Filenames</title>
<p>Most modern operating systems support Unicode filenames in some way.
There are many different ways to do this and Erlang by default treats the
different approaches differently:</p>
@@ -855,8 +855,12 @@ Eshell V5.10.1 (abort with ^G)
</note>
<section>
- <title>Notes About Raw Filenames</title>
<marker id="notes-about-raw-filenames"/>
+ <title>Notes About Raw Filenames</title>
+ <note><p>
+ Note that raw filenames <em>not</em> necessarily are encoded the
+ same way as on the OS level.
+ </p></note>
<p>Raw filenames were introduced together with Unicode filename support
in ERTS 5.8.2 (Erlang/OTP R14B01). The reason &quot;raw
filenames&quot; were introduced in the system was