Fix minor problems found by static checking.

* coding.c (encode_inhibit_flag, inhibit_flag): New functions.
Redo the latter's body to sidestep GCC parenthesization warnings.
(setup_coding_system, detect_coding, detect_coding_system): Use them.
* coding.c (detect_coding, detect_coding_system):
* coding.h (struct undecided_spec):
Use bool for boolean.
* image.c (QCmax_width, QCmax_height): Now static.
* xdisp.c (Fmove_point_visually): Remove unused local.

5 files changed, 53 insertions, 36 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 1e1b54a72d0..521e18583a5 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,15 @@
+2013-06-29  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Fix minor problems found by static checking.
+        * coding.c (encode_inhibit_flag, inhibit_flag): New functions.
+        Redo the latter's body to sidestep GCC parenthesization warnings.
+        (setup_coding_system, detect_coding, detect_coding_system): Use them.
+        * coding.c (detect_coding, detect_coding_system):
+        * coding.h (struct undecided_spec):
+        Use bool for boolean.
+        * image.c (QCmax_width, QCmax_height): Now static.
+        * xdisp.c (Fmove_point_visually): Remove unused local.
+
 2013-06-29  Eli Zaretskii  <eliz@gnu.org>
 
         * xdisp.c (Fmove_point_visually): New function.
diff --git a/src/coding.c b/src/coding.c
index c4aaefa8182..1ab59294b98 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -649,6 +649,23 @@ static struct coding_system coding_categories[coding_category_max];
 #define max(a, b) ((a) > (b) ? (a) : (b))
 #endif
 
+/* Encode a flag that can be nil, something else, or t as -1, 0, 1.  */
+
+static int
+encode_inhibit_flag (Lisp_Object flag)
+{
+  return NILP (flag) ? -1 : EQ (flag, Qt);
+}
+
+/* True if the value of ENCODED_FLAG says a flag should be treated as set.
+   1 means yes, -1 means no, 0 means ask the user variable VAR.  */
+
+static bool
+inhibit_flag (int encoded_flag, bool var)
+{
+  return 0 < encoded_flag + var;
+}
+
 #define CODING_GET_INFO(coding, attrs, charset_list)    \
   do {                                                  \
     (attrs) = CODING_ID_ATTRS ((coding)->id);           \
@@ -5706,17 +5723,11 @@ setup_coding_system (Lisp_Object coding_system, struct coding_system *coding)
       coding->encoder = encode_coding_raw_text;
       coding->common_flags |= CODING_REQUIRE_DETECTION_MASK;
       coding->spec.undecided.inhibit_nbd
-        = (NILP (AREF (attrs, coding_attr_undecided_inhibit_null_byte_detection))
-           ? -1
-           : EQ (AREF (attrs, coding_attr_undecided_inhibit_null_byte_detection), Qt)
-           ? 1
-           : 0);
+        = (encode_inhibit_flag
+           (AREF (attrs, coding_attr_undecided_inhibit_null_byte_detection)));
       coding->spec.undecided.inhibit_ied
-        = (NILP (AREF (attrs, coding_attr_undecided_inhibit_iso_escape_detection))
-           ? -1
-           : EQ (AREF (attrs, coding_attr_undecided_inhibit_iso_escape_detection), Qt)
-           ? 1
-           : 0);
+        = (encode_inhibit_flag
+           (AREF (attrs, coding_attr_undecided_inhibit_iso_escape_detection)));
       coding->spec.undecided.prefer_utf_8
         = ! NILP (AREF (attrs, coding_attr_undecided_prefer_utf_8));
     }
@@ -6476,16 +6487,11 @@ detect_coding (struct coding_system *coding)
       int c, i;
       struct coding_detection_info detect_info;
       bool null_byte_found = 0, eight_bit_found = 0;
-      int inhibit_nbd           /* null byte detection */
-        = (coding->spec.undecided.inhibit_nbd > 0
-           | (coding->spec.undecided.inhibit_nbd == 0
-              & inhibit_null_byte_detection));
-      int inhibit_ied           /* iso escape detection */
-        = (coding->spec.undecided.inhibit_ied > 0
-           | (coding->spec.undecided.inhibit_ied == 0
-              & inhibit_iso_escape_detection));
-      int prefer_utf_8
-        = coding->spec.undecided.prefer_utf_8;
+      bool inhibit_nbd = inhibit_flag (coding->spec.undecided.inhibit_nbd,
+                                       inhibit_null_byte_detection);
+      bool inhibit_ied = inhibit_flag (coding->spec.undecided.inhibit_ied,
+                                       inhibit_iso_escape_detection);
+      bool prefer_utf_8 = coding->spec.undecided.prefer_utf_8;
 
       coding->head_ascii = 0;
       detect_info.checked = detect_info.found = detect_info.rejected = 0;
@@ -8544,17 +8550,11 @@ detect_coding_system (const unsigned char *src,
       enum coding_category category IF_LINT (= 0);
       struct coding_system *this IF_LINT (= NULL);
       int c, i;
-      int inhibit_nbd           /* null byte detection */
-        = (coding.spec.undecided.inhibit_nbd > 0
-           | (coding.spec.undecided.inhibit_nbd == 0
-              & inhibit_null_byte_detection));
-      int inhibit_ied           /* iso escape detection */
-        = (coding.spec.undecided.inhibit_ied > 0
-           | (coding.spec.undecided.inhibit_ied == 0
-              & inhibit_iso_escape_detection));
-      int prefer_utf_8
-        = coding.spec.undecided.prefer_utf_8;
-
+      bool inhibit_nbd = inhibit_flag (coding.spec.undecided.inhibit_nbd,
+                                       inhibit_null_byte_detection);
+      bool inhibit_ied = inhibit_flag (coding.spec.undecided.inhibit_ied,
+                                       inhibit_iso_escape_detection);
+      bool prefer_utf_8 = coding.spec.undecided.prefer_utf_8;
 
       /* Skip all ASCII bytes except for a few ISO2022 controls.  */
       for (; src < src_end; src++)
diff --git a/src/coding.h b/src/coding.h
index 453805e233a..7b7078e06fa 100644
--- a/src/coding.h
+++ b/src/coding.h
@@ -382,9 +382,15 @@ struct ccl_spec;
 
 struct undecided_spec
 {
-  int inhibit_nbd;              /* nbd: null byte detection */
-  int inhibit_ied;              /* ied: iso escape detection */
-  int prefer_utf_8;
+  /* Inhibit null byte detection.  1 means always inhibit,
+     -1 means do not inhibit, 0 means rely on user variable.  */
+  int inhibit_nbd;
+
+  /* Inhibit ISO escape detection.  -1, 0, 1 as above.  */
+  int inhibit_ied;
+
+  /* Prefer UTF-8 when the input could be other encodings.  */
+  bool prefer_utf_8;
 };
 
 enum utf_bom_type
diff --git a/src/image.c b/src/image.c
index d5d5d4053f9..2c288342028 100644
--- a/src/image.c
+++ b/src/image.c
@@ -130,7 +130,7 @@ static void free_color_table (void);
 static unsigned long *colors_in_color_table (int *n);
 #endif
 
-Lisp_Object QCmax_width, QCmax_height;
+static Lisp_Object QCmax_width, QCmax_height;
 
 /* Code to deal with bitmaps.  Bitmaps are referenced by their bitmap
    id, which is just an int that this section returns.  Bitmaps are
diff --git a/src/xdisp.c b/src/xdisp.c
index 420ff0c918b..963553e10cc 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -20252,7 +20252,6 @@ Value is the new character position of point.  */)
       struct it it;
       int pt_x, target_x, pixel_width, pt_vpos;
       bool at_eol_p;
-      bool disp_string_at_start_p = 0;
       bool overshoot_expected = false;
       bool target_is_eol_p = false;