[m-rev.] diff: Fix some uninitialised variables in error paths.

[Peter Wang]

browser/util.m:
compiler/equiv_type_hlds.m:
compiler/inst_test.m:
library/construct.m:
library/io.m:
    Ensure output variables are initialised in all code paths.

diff --git a/browser/util.m b/browser/util.m
index 54f4181f8..4e2bb0975 100644
--- a/browser/util.m
+++ b/browser/util.m
@@ -96,7 +96,7 @@ trace_getline(Prompt, Result, MdbIn, MdbOut, !IO) :-
     % which only works for will_not_call_mercury foreign_procs.
     [will_not_call_mercury, promise_pure, tabled_for_io],
 "
-    char        *line;
+    char        *line = NULL;
     MercuryFile *mdb_in = (MercuryFile *) MdbIn;
     MercuryFile *mdb_out = (MercuryFile *) MdbOut;
 
diff --git a/compiler/equiv_type_hlds.m b/compiler/equiv_type_hlds.m
index 772e2109a..f6f51a44f 100644
--- a/compiler/equiv_type_hlds.m
+++ b/compiler/equiv_type_hlds.m
@@ -1138,6 +1138,7 @@ static  TypeInInstCacheEntry  type_in_inst_cache[TYPE_IN_INST_CACHE_SIZE];
         MayOccur = type_in_inst_cache[hash].tice_may_occur;
     } else {
         Found = MR_BOOL_NO;
+        MayOccur = MR_BOOL_NO;
     }
 ").
 
diff --git a/compiler/inst_test.m b/compiler/inst_test.m
index 8990cad9c..472de0347 100644
--- a/compiler/inst_test.m
+++ b/compiler/inst_test.m
@@ -302,6 +302,7 @@ static  InstIsGroundCacheEntry
         IsGround = inst_is_ground_cache[hash].iig_is_ground;
     } else {
         Found = MR_BOOL_NO;
+        IsGround = MR_NO;
     }
 ").
 
diff --git a/library/construct.m b/library/construct.m
index a2fca5ca1..850f9355f 100644
--- a/library/construct.m
+++ b/library/construct.m
@@ -480,7 +480,8 @@ get_functor_ordinal(TypeDesc, FunctorNumber, Ordinal) :-
         case MR_TYPECTOR_REP_UNUSED2:
         case MR_TYPECTOR_REP_UNKNOWN:
             success = MR_FALSE;
-
+            Ordinal = 0;
+            break;
         }
     }
     SUCCESS_INDICATOR = success;
diff --git a/library/io.m b/library/io.m
index 42f7484d9..4631357e8 100644
--- a/library/io.m
+++ b/library/io.m
@@ -6114,11 +6114,12 @@ read_char_code(input_stream(Stream), ResultCode, Char, Error, !IO) :-
         if (MR_FERROR(*Stream)) {
             ResultCode = ML_RESULT_CODE_ERROR;
             Error = errno;
+            Char = 0;
         } else {
             ResultCode = ML_RESULT_CODE_EOF;
             Error = 0;
+            Char = 0;
         }
-        Char = 0;
     } else {
         if ((uc & 0xE0) == 0xC0) {
             nbytes = 2;
@@ -14236,24 +14237,23 @@ decode_system_command_exit_code(Code0) = Status :-
     [will_not_call_mercury, thread_safe, promise_pure,
         does_not_affect_liveness, no_sharing],
 "
+    Exited = MR_NO;
+    Status = 0;
+    Signalled = MR_NO;
+    Signal = 0;
+
     #if defined (WIFEXITED) && defined (WEXITSTATUS) && \
             defined (WIFSIGNALED) && defined (WTERMSIG)
         if (WIFEXITED(Status0)) {
             Exited = MR_YES;
-            Signalled = MR_NO;
             Status = WEXITSTATUS(Status0);
         } else if (WIFSIGNALED(Status0)) {
-            Exited = MR_NO;
             Signalled = MR_YES;
             Signal = -WTERMSIG(Status0);
-        } else {
-            Exited = MR_NO;
-            Signalled = MR_NO;
         }
     #else
         Exited = MR_YES;
         Status = Status0;
-        Signalled = MR_NO;
     #endif
 ").
 
-- 
2.27.0