tags/pcre-3.1/ChangeLog

ChangeLog for PCRE
------------------


Version 2.04 18-Feb-99
----------------------

1. For parenthesized subpatterns with repeats whose minimum was zero, the
computation of the store needed to hold the pattern was incorrect (too large).
If such patterns were nested a few deep, this could multiply and become a real
problem.

2. Added /M option to pcretest to show the memory requirement of a specific
pattern. Made -m a synonym of -s (which does this globally) for compatibility.

3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
compiled in such a way that the backtracking after subsequent failure was
pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.


Version 2.03 02-Feb-99
----------------------

1. Fixed typo and small mistake in man page.

2. Added 4th condition (GPL supersedes if conflict) and created separate
LICENCE file containing the conditions.

3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
Perl, that is the internal \ allows the delimiter to be included in the
pattern. Locked out the use of \ as a delimiter. If \ immediately follows
the final delimiter, add \ to the end of the pattern (to test the error).

4. Added the convenience functions for extracting substrings after a successful
match. Updated pcretest to make it able to test these functions.


Version 2.02 14-Jan-99
----------------------

1. Initialized the working variables associated with each extraction so that
their saving and restoring doesn't refer to uninitialized store.

2. Put dummy code into study.c in order to trick the optimizer of the IBM C
compiler for OS/2 into generating correct code. Apparently IBM isn't going to
fix the problem.

3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
calls, and wasn't printing the correct value for compiling calls. Increased the
default value of LOOPREPEAT, and the number of significant figures in the
times.

4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.

5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
a building problem on Windows NT with a FAT file system.


Version 2.01 21-Oct-98
----------------------

1. Changed the API for pcre_compile() to allow for the provision of a pointer
to character tables built by pcre_maketables() in the current locale. If NULL
is passed, the default tables are used.


Version 2.00 24-Sep-98
----------------------

1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
it any more.

2. Allow quantification of (?>) groups, and make it work correctly.

3. The first character computation wasn't working for (?>) groups.

4. Correct the implementation of \Z (it is permitted to match on the \n at the
end of the subject) and add 5.005's \z, which really does match only at the
very end of the subject.

5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.

6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
localized options. All options to pcre_study() were also removed.

7. Add other new features from 5.005:

   $(?<=           positive lookbehind
   $(?<!           negative lookbehind
   (?imsx-imsx)    added the unsetting capability
                   such a setting is global if at outer level; local otherwise
   (?imsx-imsx:)   non-capturing groups with option setting
   (?(cond)re|re)  conditional pattern matching

   A backreference to itself in a repeated group matches the previous
   captured string.

8. General tidying up of studying (both automatic and via "study")
consequential on the addition of new assertions.

9. As in 5.005, unlimited repeated groups that could match an empty substring
are no longer faulted at compile time. Instead, the loop is forcibly broken at
runtime if any iteration does actually match an empty substring.

10. Include the RunTest script in the distribution.

11. Added tests from the Perl 5.005_02 distribution. This showed up a few
discrepancies, some of which were old and were also with respect to 5.004. They
have now been fixed.


Version 1.09 28-Apr-98
----------------------

1. A negated single character class followed by a quantifier with a minimum
value of one (e.g.  [^x]{1,6}  ) was not compiled correctly. This could lead to
program crashes, or just wrong answers. This did not apply to negated classes
containing more than one character, or to minima other than one.


Version 1.08 27-Mar-98
----------------------

1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.

2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
latter must appear before anything that relies on it in the pattern.


Version 1.07 16-Feb-98
----------------------

1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
repeat of a potentially empty string).


Version 1.06 23-Jan-98
----------------------

1. Added Markus Oberhumer's little patches for C++.

2. Literal strings longer than 255 characters were broken.


Version 1.05 23-Dec-97
----------------------

1. Negated character classes containing more than one character were failing if
PCRE_CASELESS was set at run time.


Version 1.04 19-Dec-97
----------------------

1. Corrected the man page, where some "const" qualifiers had been omitted.

2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
input syntax.

3. Fixed memory leak which occurred when a regex with back references was
matched with an offsets vector that wasn't big enough. The temporary memory
that is used in this case wasn't being freed if the match failed.

4. Tidied pcretest to ensure it frees memory that it gets.

5. Temporary memory was being obtained in the case where the passed offsets
vector was exactly big enough.

6. Corrected definition of offsetof() from change 5 below.

7. I had screwed up change 6 below and broken the rules for the use of
setjmp(). Now fixed.


Version 1.03 18-Dec-97
----------------------

1. A erroneous regex with a missing opening parenthesis was correctly
diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
on some systems.

2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
it was reported that one broken compiler failed on the former because "code" is
also an independent variable.

3. The erroneous regex a[]b caused an array overrun reference.

4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
fail on data ending with that character. (It was going on too far, and checking
the next character, typically a binary zero.) This was specific to the
optimized code for single-character negative classes.

5. Added a contributed patch from the TIN world which does the following:

  + Add an undef for memmove, in case the the system defines a macro for it.

  + Add a definition of offsetof(), in case there isn't one. (I don't know
    the reason behind this - offsetof() is part of the ANSI standard - but
    it does no harm).

  + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
    most of the places where whitespace preceded '#'. I have given up and
    allowed the remaining 2 cases to be at the margin.

  + Rename some variables in pcre to eliminate shadowing. This seems very
    pedantic, but does no harm, of course.

6. Moved the call to setjmp() into its own function, to get rid of warnings
from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.

7. Constructs such as \d{8,} were compiling into the equivalent of
\d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
outcome, but in this particular case used more store than had been allocated,
which caused the bug to be discovered because it threw up an internal error.

8. The debugging code in both pcre and pcretest for outputting the compiled
form of a regex was going wrong in the case of back references followed by
curly-bracketed repeats.


Version 1.02 12-Dec-97
----------------------

1. Typos in pcre.3 and comments in the source fixed.

2. Applied a contributed patch to get rid of places where it used to remove
'const' from variables, and fixed some signed/unsigned and uninitialized
variable warnings.

3. Added the "runtest" target to Makefile.

4. Set default compiler flag to -O2 rather than just -O.


Version 1.01 19-Nov-97
----------------------

1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
like /([ab]*)*/, that is, for classes with more than one character in them.

2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
as /((?>a*))*/ (a PCRE_EXTRA facility).


Version 1.00 18-Nov-97
----------------------

1. Added compile-time macros to support systems such as SunOS4 which don't have
memmove() or strerror() but have other things that can be used instead.

2. Arranged that "make clean" removes the executables.


Version 0.99 27-Oct-97
----------------------

1. Fixed bug in code for optimizing classes with only one character. It was
initializing a 32-byte map regardless, which could cause it to run off the end
of the memory it had got.

2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.


Version 0.98 22-Oct-97
----------------------

1. Fixed bug in code for handling temporary memory usage when there are more
back references than supplied space in the ovector. This could cause segfaults.


Version 0.97 21-Oct-97
----------------------

1. Added the \X "cut" facility, conditional on PCRE_EXTRA.

2. Optimized negated single characters not to use a bit map.

3. Brought error texts together as macro definitions; clarified some of them;
fixed one that was wrong - it said "range out of order" when it meant "invalid
escape sequence".

4. Changed some char * arguments to const char *.

5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).

6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
pcretest.


Version 0.96 16-Oct-97
----------------------

1. Added a simple "pgrep" utility to the distribution.

2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
where "ddd" means "one or more decimal digits".

3. Fixed serious bug. If a pattern had a back reference, but the call to
pcre_exec() didn't supply a large enough ovector to record the related
identifying subpattern, the match always failed. PCRE now remembers the number
of the largest back reference, and gets some temporary memory in which to save
the offsets during matching if necessary, in order to ensure that
backreferences always work.

4. Increased the compatibility with Perl in a number of ways:

  (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
      to request this handling. The option can be set at compile or exec time.

  (b) $ matches before a terminating newline by default; an option
      PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
      mode). The option can be set at compile or exec time.

  (c) The handling of \ followed by a digit other than 0 is now supposed to be
      the same as Perl's. If the decimal number it represents is less than 10
      or there aren't that many previous left capturing parentheses, an octal
      escape is read. Inside a character class, it's always an octal escape,
      even if it is a single digit.

  (d) An escaped but undefined alphabetic character is taken as a literal,
      unless PCRE_EXTRA is set. Currently this just reserves the remaining
      escapes.

  (e) {0} is now permitted. (The previous item is removed from the compiled
      pattern).

5. Changed all the names of code files so that the basic parts are no longer
than 10 characters, and abolished the teeny "globals.c" file.

6. Changed the handling of character classes; they are now done with a 32-byte
bit map always.

7. Added the -d and /D options to pcretest to make it possible to look at the
internals of compilation without having to recompile pcre.


Version 0.95 23-Sep-97
----------------------

1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
\x20 at the start of a run of normal characters. These were being treated as
real characters, instead of the source characters being re-checked.


Version 0.94 18-Sep-97
----------------------

1. The functions are now thread-safe, with the caveat that the global variables
containing pointers to malloc() and free() or alternative functions are the
same for all threads.

2. Get pcre_study() to generate a bitmap of initial characters for non-
anchored patterns when this is possible, and use it if passed to pcre_exec().


Version 0.93 15-Sep-97
----------------------

1. /(b)|(:+)/ was computing an incorrect first character.

2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
but not actually doing anything yet.

3. Treat "-" characters in classes that cannot be part of ranges as literals,
as Perl does (e.g. [-az] or [az-]).

4. Set the anchored flag if a branch starts with .* or .*? because that tests
all possible positions.

5. Split up into different modules to avoid including unneeded functions in a
compiled binary. However, compile and exec are still in one module. The "study"
function is split off.

6. The character tables are now in a separate module whose source is generated
by an auxiliary program - but can then be edited by hand if required. There are
now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
toupper() in the code.

7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
make them global. Abolish the function for setting them, as the caller can now
set them directly.


Version 0.92 11-Sep-97
----------------------

1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
(e.g. /a{1,3}/) was broken (I mis-optimized it).

2. Caseless matching was not working in character classes if the characters in
the pattern were in upper case.

3. Make ranges like [W-c] work in the same way as Perl for caseless matching.

4. Make PCRE_ANCHORED public and accept as a compile option.

5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
pass them.

6. Give an error if bad option bits passed at compile or run time.

7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
pcretest to cause it to pass that flag.

8. Add pcre_info(), to get the number of identifying subpatterns, the stored
options, and the first character, if set.

9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.


Version 0.91 10-Sep-97
----------------------

1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
match the empty string as in /(a*)*/. It was looping and ultimately crashing.

2. PCRE was looping on encountering an indefinitely repeated back reference to
a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
Perl does - treats the match as successful.

****
1	ChangeLog for PCRE
2	------------------
3
4
5	Version 2.04 18-Feb-99
6	----------------------
7
8	1. For parenthesized subpatterns with repeats whose minimum was zero, the
9	computation of the store needed to hold the pattern was incorrect (too large).
10	If such patterns were nested a few deep, this could multiply and become a real
11	problem.
12
13	2. Added /M option to pcretest to show the memory requirement of a specific
14	pattern. Made -m a synonym of -s (which does this globally) for compatibility.
15
16	3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
17	compiled in such a way that the backtracking after subsequent failure was
18	pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
19	((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
20
21
22	Version 2.03 02-Feb-99
23	----------------------
24
25	1. Fixed typo and small mistake in man page.
26
27	2. Added 4th condition (GPL supersedes if conflict) and created separate
28	LICENCE file containing the conditions.
29
30	3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
31	Perl, that is the internal \ allows the delimiter to be included in the
32	pattern. Locked out the use of \ as a delimiter. If \ immediately follows
33	the final delimiter, add \ to the end of the pattern (to test the error).
34
35	4. Added the convenience functions for extracting substrings after a successful
36	match. Updated pcretest to make it able to test these functions.
37
38
39	Version 2.02 14-Jan-99
40	----------------------
41
42	1. Initialized the working variables associated with each extraction so that
43	their saving and restoring doesn't refer to uninitialized store.
44
45	2. Put dummy code into study.c in order to trick the optimizer of the IBM C
46	compiler for OS/2 into generating correct code. Apparently IBM isn't going to
47	fix the problem.
48
49	3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
50	calls, and wasn't printing the correct value for compiling calls. Increased the
51	default value of LOOPREPEAT, and the number of significant figures in the
52	times.
53
54	4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
55
56	5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
57	a building problem on Windows NT with a FAT file system.
58
59
60	Version 2.01 21-Oct-98
61	----------------------
62
63	1. Changed the API for pcre_compile() to allow for the provision of a pointer
64	to character tables built by pcre_maketables() in the current locale. If NULL
65	is passed, the default tables are used.
66
67
68	Version 2.00 24-Sep-98
69	----------------------
70
71	1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
72	it any more.
73
74	2. Allow quantification of (?>) groups, and make it work correctly.
75
76	3. The first character computation wasn't working for (?>) groups.
77
78	4. Correct the implementation of \Z (it is permitted to match on the \n at the
79	end of the subject) and add 5.005's \z, which really does match only at the
80	very end of the subject.
81
82	5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
83
84	6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
85	DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
86	localized options. All options to pcre_study() were also removed.
87
88	7. Add other new features from 5.005:
89
90	$(?<= positive lookbehind
91	$(?<! negative lookbehind
92	(?imsx-imsx) added the unsetting capability
93	such a setting is global if at outer level; local otherwise
94	(?imsx-imsx:) non-capturing groups with option setting
95	(?(cond)re\|re) conditional pattern matching
96
97	A backreference to itself in a repeated group matches the previous
98	captured string.
99
100	8. General tidying up of studying (both automatic and via "study")
101	consequential on the addition of new assertions.
102
103	9. As in 5.005, unlimited repeated groups that could match an empty substring
104	are no longer faulted at compile time. Instead, the loop is forcibly broken at
105	runtime if any iteration does actually match an empty substring.
106
107	10. Include the RunTest script in the distribution.
108
109	11. Added tests from the Perl 5.005_02 distribution. This showed up a few
110	discrepancies, some of which were old and were also with respect to 5.004. They
111	have now been fixed.
112
113
114	Version 1.09 28-Apr-98
115	----------------------
116
117	1. A negated single character class followed by a quantifier with a minimum
118	value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
119	program crashes, or just wrong answers. This did not apply to negated classes
120	containing more than one character, or to minima other than one.
121
122
123	Version 1.08 27-Mar-98
124	----------------------
125
126	1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
127
128	2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
129	latter must appear before anything that relies on it in the pattern.
130
131
132	Version 1.07 16-Feb-98
133	----------------------
134
135	1. A pattern such as /((a))/ was not being diagnosed as in error (unlimited
136	repeat of a potentially empty string).
137
138
139	Version 1.06 23-Jan-98
140	----------------------
141
142	1. Added Markus Oberhumer's little patches for C++.
143
144	2. Literal strings longer than 255 characters were broken.
145
146
147	Version 1.05 23-Dec-97
148	----------------------
149
150	1. Negated character classes containing more than one character were failing if
151	PCRE_CASELESS was set at run time.
152
153
154	Version 1.04 19-Dec-97
155	----------------------
156
157	1. Corrected the man page, where some "const" qualifiers had been omitted.
158
159	2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
160	input syntax.
161
162	3. Fixed memory leak which occurred when a regex with back references was
163	matched with an offsets vector that wasn't big enough. The temporary memory
164	that is used in this case wasn't being freed if the match failed.
165
166	4. Tidied pcretest to ensure it frees memory that it gets.
167
168	5. Temporary memory was being obtained in the case where the passed offsets
169	vector was exactly big enough.
170
171	6. Corrected definition of offsetof() from change 5 below.
172
173	7. I had screwed up change 6 below and broken the rules for the use of
174	setjmp(). Now fixed.
175
176
177	Version 1.03 18-Dec-97
178	----------------------
179
180	1. A erroneous regex with a missing opening parenthesis was correctly
181	diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
182	on some systems.
183
184	2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
185	it was reported that one broken compiler failed on the former because "code" is
186	also an independent variable.
187
188	3. The erroneous regex a[]b caused an array overrun reference.
189
190	4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
191	fail on data ending with that character. (It was going on too far, and checking
192	the next character, typically a binary zero.) This was specific to the
193	optimized code for single-character negative classes.
194
195	5. Added a contributed patch from the TIN world which does the following:
196
197	+ Add an undef for memmove, in case the the system defines a macro for it.
198
199	+ Add a definition of offsetof(), in case there isn't one. (I don't know
200	the reason behind this - offsetof() is part of the ANSI standard - but
201	it does no harm).
202
203	+ Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
204	most of the places where whitespace preceded '#'. I have given up and
205	allowed the remaining 2 cases to be at the margin.
206
207	+ Rename some variables in pcre to eliminate shadowing. This seems very
208	pedantic, but does no harm, of course.
209
210	6. Moved the call to setjmp() into its own function, to get rid of warnings
211	from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
212
213	7. Constructs such as \d{8,} were compiling into the equivalent of
214	\d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
215	outcome, but in this particular case used more store than had been allocated,
216	which caused the bug to be discovered because it threw up an internal error.
217
218	8. The debugging code in both pcre and pcretest for outputting the compiled
219	form of a regex was going wrong in the case of back references followed by
220	curly-bracketed repeats.
221
222
223	Version 1.02 12-Dec-97
224	----------------------
225
226	1. Typos in pcre.3 and comments in the source fixed.
227
228	2. Applied a contributed patch to get rid of places where it used to remove
229	'const' from variables, and fixed some signed/unsigned and uninitialized
230	variable warnings.
231
232	3. Added the "runtest" target to Makefile.
233
234	4. Set default compiler flag to -O2 rather than just -O.
235
236
237	Version 1.01 19-Nov-97
238	----------------------
239
240	1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
241	like /([ab])/, that is, for classes with more than one character in them.
242
243	2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
244	as /((?>a))/ (a PCRE_EXTRA facility).
245
246
247	Version 1.00 18-Nov-97
248	----------------------
249
250	1. Added compile-time macros to support systems such as SunOS4 which don't have
251	memmove() or strerror() but have other things that can be used instead.
252
253	2. Arranged that "make clean" removes the executables.
254
255
256	Version 0.99 27-Oct-97
257	----------------------
258
259	1. Fixed bug in code for optimizing classes with only one character. It was
260	initializing a 32-byte map regardless, which could cause it to run off the end
261	of the memory it had got.
262
263	2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
264
265
266	Version 0.98 22-Oct-97
267	----------------------
268
269	1. Fixed bug in code for handling temporary memory usage when there are more
270	back references than supplied space in the ovector. This could cause segfaults.
271
272
273	Version 0.97 21-Oct-97
274	----------------------
275
276	1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
277
278	2. Optimized negated single characters not to use a bit map.
279
280	3. Brought error texts together as macro definitions; clarified some of them;
281	fixed one that was wrong - it said "range out of order" when it meant "invalid
282	escape sequence".
283
284	4. Changed some char * arguments to const char *.
285
286	5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
287
288	6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
289	pcretest.
290
291
292	Version 0.96 16-Oct-97
293	----------------------
294
295	1. Added a simple "pgrep" utility to the distribution.
296
297	2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
298	unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
299	where "ddd" means "one or more decimal digits".
300
301	3. Fixed serious bug. If a pattern had a back reference, but the call to
302	pcre_exec() didn't supply a large enough ovector to record the related
303	identifying subpattern, the match always failed. PCRE now remembers the number
304	of the largest back reference, and gets some temporary memory in which to save
305	the offsets during matching if necessary, in order to ensure that
306	backreferences always work.
307
308	4. Increased the compatibility with Perl in a number of ways:
309
310	(a) . no longer matches \n by default; an option PCRE_DOTALL is provided
311	to request this handling. The option can be set at compile or exec time.
312
313	(b) $ matches before a terminating newline by default; an option
314	PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
315	mode). The option can be set at compile or exec time.
316
317	(c) The handling of \ followed by a digit other than 0 is now supposed to be
318	the same as Perl's. If the decimal number it represents is less than 10
319	or there aren't that many previous left capturing parentheses, an octal
320	escape is read. Inside a character class, it's always an octal escape,
321	even if it is a single digit.
322
323	(d) An escaped but undefined alphabetic character is taken as a literal,
324	unless PCRE_EXTRA is set. Currently this just reserves the remaining
325	escapes.
326
327	(e) {0} is now permitted. (The previous item is removed from the compiled
328	pattern).
329
330	5. Changed all the names of code files so that the basic parts are no longer
331	than 10 characters, and abolished the teeny "globals.c" file.
332
333	6. Changed the handling of character classes; they are now done with a 32-byte
334	bit map always.
335
336	7. Added the -d and /D options to pcretest to make it possible to look at the
337	internals of compilation without having to recompile pcre.
338
339
340	Version 0.95 23-Sep-97
341	----------------------
342
343	1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
344	\x20 at the start of a run of normal characters. These were being treated as
345	real characters, instead of the source characters being re-checked.
346
347
348	Version 0.94 18-Sep-97
349	----------------------
350
351	1. The functions are now thread-safe, with the caveat that the global variables
352	containing pointers to malloc() and free() or alternative functions are the
353	same for all threads.
354
355	2. Get pcre_study() to generate a bitmap of initial characters for non-
356	anchored patterns when this is possible, and use it if passed to pcre_exec().
357
358
359	Version 0.93 15-Sep-97
360	----------------------
361
362	1. /(b)\|(:+)/ was computing an incorrect first character.
363
364	2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
365	but not actually doing anything yet.
366
367	3. Treat "-" characters in classes that cannot be part of ranges as literals,
368	as Perl does (e.g. [-az] or [az-]).
369
370	4. Set the anchored flag if a branch starts with .* or .*? because that tests
371	all possible positions.
372
373	5. Split up into different modules to avoid including unneeded functions in a
374	compiled binary. However, compile and exec are still in one module. The "study"
375	function is split off.
376
377	6. The character tables are now in a separate module whose source is generated
378	by an auxiliary program - but can then be edited by hand if required. There are
379	now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
380	toupper() in the code.
381
382	7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
383	make them global. Abolish the function for setting them, as the caller can now
384	set them directly.
385
386
387	Version 0.92 11-Sep-97
388	----------------------
389
390	1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
391	(e.g. /a{1,3}/) was broken (I mis-optimized it).
392
393	2. Caseless matching was not working in character classes if the characters in
394	the pattern were in upper case.
395
396	3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
397
398	4. Make PCRE_ANCHORED public and accept as a compile option.
399
400	5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
401	PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
402	pass them.
403
404	6. Give an error if bad option bits passed at compile or run time.
405
406	7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
407	pcretest to cause it to pass that flag.
408
409	8. Add pcre_info(), to get the number of identifying subpatterns, the stored
410	options, and the first character, if set.
411
412	9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
413
414
415	Version 0.91 10-Sep-97
416	----------------------
417
418	1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
419	match the empty string as in /(a)/. It was looping and ultimately crashing.
420
421	2. PCRE was looping on encountering an indefinitely repeated back reference to
422	a subpattern that had matched an empty string, e.g. /(a\|)\1*/. It now does what
423	Perl does - treats the match as successful.
424
425	****